The plan for 2012 is a slightly different one. There’s nothing left to prove, both car and driver have demonstrated that they can win a championship. What we need now is to up the pace just that little bit more, and then turn him loose to go and play. This year is about fun, not results. The pressure of points tables and strategic driving, no matter how little you admit it to yourself, is totally different to the joy of slinging your car at the track with a sense of wonder that you’re still alive afterwards.

In terms of upgrades for the car then, very few are really on the cards. The stainless exhaust that she borrowed late last year is to stay on, but the power is otherwise not likely to change a great deal, it’s not the plan.

The old girl needs a windscreen. Thoroughly starred by gravel from a certain Mr Lyddall’s rear tyres, there’s no choice in this. The guys from Yorkshire Windscreens are familiar with us by this point, and they are booked to perform their usual fascinating magic because the facelift car has a bonded screen that we can’t therefore fit.

We remove the screen trim to save time and therefore money, and what lies beneath is rather disturbing, there’s not a lot of beneath left. To be honest I don’t quite know what Jaguar were thinking with the facelift screen design. Bond the screen in and then let the water flow freely beneath the trim. We all know that if you let water in and then hold it there with rubbers, with foam, with trim, it doesn’t matter how good your waterproofing is, at some point it’s going to get in, and it’s going to rust. Well, this one has done. The angle grinder flays the rust off the scuttle, the screen pillars and those pesky rust bubbles above the screen.

Out come the cereal boxes to make templates for the missing metal. Our trusty second-hand welder is commissioned to apply the steel glue, and helpfully coughs, rolls over and dies after four seconds. A swift trip to the shop heralds the arrival of Miguel the Brand New welder, which is certainly a first for us.

With the pillars repaired, the scuttle reattached, and more grinding than I had planned for my day off, she is back into what looks a bit like Jaguar shape. Making these repairs when there is literally nothing to copy is not simple, but it looks like it might work. A coat of the loathsome Hammerite does make sense in this application, it does get hold of bare metal pretty well, and it can be daubed on quite thickly to help prevent recurrence, we’re happy that the repairs will now outlast the car.

The proof of the pudding was the screen fitment. It went in. Good enough for me, we must have got it about right. Refitting the trim allowed for a gentle departure from original, lashings of silicone sealant. I don’t care what the plan was, but water isn’t getting in here now, it can use the gutters like everyone else.

Paint repair is going to be tricky. The roof now needs paint above the screen. I don’t really want to paint the whole roof, because that means rear wings too. I’ve never successfully blended a paint join on a major panel, and this one is pretty damned big.

The scuttle needed work too, low spots from the bashings and heat distortion need to be made good, and of course the pull cables run through here. Peeling the stickers off leaves a few questions, like why is there what is clearly a large angle-grinder gouge beneath one of them, and in what universe is covering it with a sticker normal practice?

Second question was how do the pull cables come out, because I can’t find the nuts. To fit the cables here you have to pierce both skins, the scuttle is a double-skinned panel. A pull cable is itself a threaded item, and you need to attach a nut to it to pull it in tight, usually. For a Kutukan this means getting a hole cutter to the inside skin from inside the car, to make a hole big enough to get a spanner in there. It’s not a lot of fun, and someone here has decided not to bother.

There’s no nut on these, there’s no way to get to the back. They appear to have been screwed into using the metal of the car as the nut. This is pretty dicey behaviour, because that thin skim of steel isn’t really up to the job, a panicked yank by a marshall could pull it all the way out.

Repairs are swift. Amazingly the paint does successfully blend, the problem being that the existing silver on the roof from whoever rid the car of the red stripe wasn’t exactly a great finish, and the new repair blends the gloss of fresh lacquer into the dull finish of the existing paint. In reality this is a bodge job. It’s a decent bodge job, and it’ll do for a race car, but it’s a 100mph paintjob, not one to win the Autoglym trophy with.

With our traditional Kutuka trackday at Cadwell looming, and my own car not ready due to the time spent on this machine, we elect to “borrow” Katrina for the day to do our own evaluation. We want a handling assessment, and to see if we can diagnose an electrical issue that Philip reported at Brands.

A day of amusement throwing cars around Cadwell did allow for some diagnostic driving amidst the merriment. The car is loose on the rear, palpable movement going on during sudden direction changes as if the rear is steering itself and hanging on to the corner for that disconcerting microgrobble of time longer after the moment you really wanted to be heading the other way. It would explain why the car is occasionally difficult to recover from oversteer, at least insofar as in-car footage suggests.

There is then the question of the electrical fault, which Philip had reported as an occasional cough mid-corner a couple of times in recent outings. This too turned out to be true, it took only half a dozen laps of hurling the car at Cadwell, Kutuka-style, to reveal a hesitation at certain throttle loadings, which cleared with application of full power.

To me it felt electrical rather than aught else, and a new coil and rotor arm appeared to clear it up a little, but made it more pronounced, the fault was less but more sharply defined. Definitely electrical.

Problem with these later cars is we don't run one.

Except we do, the Kutuka road fleet includes an identical XJS. Which currently works well, and means we have a car we can steal known, working parts from.

Electrical faults are annoying. Not being a garage we have only a limited number of options, most of which consist of phoning David, and the one thing we don't yet do is electronics. Being a race car the ability to test this is somewhat limited.

We can rule out the basics. Bear's car in 2009 had what felt like a more severe case of this problem, and we know what cured that, so that's step 1. If that doesn't work, well we'll be equipped with a large chunk of the road car as spares, and if Terry parks his XJS anywhere near us in the paddock we'll have that too.

Time to tackle the things that we can see, which we know need attention.

Brakes get a service each season on any of our cars, new seals all round. This reveals a surprising amount of corrosion to the pistons in the front calipers, to the extent that they have to be replaced. Having ended 2011 without issues and sat safely indoors for the winter, this was not expected, but it is swiftly remedied. The remaining hydraulic systems also beg for attention.

To most people the idea of annually replacing the seals in clutch and brake master cylinders would be an unnecessary expense, but the seal kits are not expensive. Do they really need doing each year? Well, you've never seen one of our cars suffer any form of hydraulic failure, so either we're plain lucky or our service schedule works. Either way, this car gets both. For the money it costs, why risk it?

Next up is weight. The rules allow 30kg to go missing. We ran 2011 with an extra 20kg of fuel aboard to get up to weight, so losing 20kg is going to be simple, stop over-filling it. The last ten, well, you can lose that in about ten minutes, or simply have the driver skip breakfast.

If we find something easy to throw away, we'll do so, but we're not going looking particularly, lightening is a gradual, organic process. Sometimes literally. The facelift cars are inherently heavier, which does make it simpler to lose.

There are a few other areas to tackle too. Cosmetically she had a few knocks in 2011, and whilst the last collision is now 7 or so months ago, some of the repairs at the time were done with haste and could be better. Given time and no damage we will be able now to bring the standard back up again and address some of the flaws. That's if it's where our time is best spent, a race car is a machine first, and pretty only if it is convenient.

The front bumper, expertly repaired by Bear at least three times now, sits a little skewed. The bumper is fine, but the car it attaches to isn't. That could be improved to square up the look of the front end. The indicators in it also need repair, one of the bulb holders is somewhere in Wales and never did make it back inside.

The passenger door took two almighty impacts in seperate races and had to be replaced.

That left a mismatch of components, XJS door, but a late one that takes an XJ40 handle, which doesn't mate to the XJS latch. Without time to invent it, we used a cable direct, the yellow loop and bright red arrow on the door explain to the marshalls that it doesn't operate as expected. A little time to invent the see-saw would perhaps rectify.

One of the electric windows has quit. The rules don't require them to work, but then I don't understand how this car gets its ventilation. The heater is in there, but not connected because it doesn't have to be. The blowers are all fitted, but there is no way to control them, the car has no heater knobs. All the parts are there, but it literally came without the knobs on, and given the blowers are off, you can't turn them on. I hadn't given it much thought, but how does Philip ventilate/demist this car in a wet race?

Drivers hang around in the rain, get their fireproofs wet, get in the car and thrash it round getting very hot, race cars steam up like mad. This one is also missing the door seals, it only came to us with one fitted, and that was nicely sliced into three pieces by the passenger door impacts. Being a facelift car, no door seals means the windows don't go to the top, so you have water that can get in, no demist function, and you can only drop one window to try and get external air into the car. It must be hell in the rain, but yet he's never complained of misting up. We need to look at that.

The diff is not a good one. Most of the powerlock has leaked out of the powerlock, it's not far from an open diff, which hurts the car in longer corners. It's not totally gone yet, but it's very close, and I know from experience how much that can hurt performance.

Replacement or refurbishment is not cheap though, so until it actually fails it won't get touched. I'd do it for my own car, but it's one of those things that you don't simply do, you have to get permission to do it.

All of this is fine-tuning stuff, rather than where we were a year ago when it was downright bloody lethal and unfit to race. We have that solid base to make into something better, and rather than those big, heroic jobs this is now a car to do those thousand little jobs on to make it better, rather than faster.

With that in mind we're still not touching the power output. It's a roadgoing class car, it should perform as such. Speed for our machinery comes from good handling and driver insanity, not expense.

There are things that could be done, but they all cost. Lighten the flywheel, front pulley and the prop. Not tuning as such, more accurately reducing the losses, rotational weight is a killer, but they are not massive, step-changes you would really notice.

It already has a decent exhaust, and big throttle. Power from a road-car engine is about as good as you're going to get without a full engine rebuild and then some big bills.

A flowed head would help. But it's costly.

Leaning on the cam timing a little might help, but there are those who have historically taken that further and fitted different Jaguar camshafts. You can't do so, I have the email from the race committee clarifying that the cams should be standard to an XJS, not to the engine, but there are folk who have done it because it's not in the published regs.

You could fit a piggyback ECU, again not outlawed by the rules, and currently seeing action on the 2012 grid, but we're not doing that either.

To us, the roadgoing class car should have a road car engine, it should work like one, and perform like a good one. So we're not playing silly with it, this thing will have the same straightline speed as everyone else in the class, and if it's faster it will be about the corners.

And that's how she is sent to Snetterton. 2012 is underway.