A £17,500, 385bhp 911: too good to be true?

Reconciling big performance with a small budget is a scary business. Largely because squeezing bang from your buck involves risk. Just look at Jeremy's £6k CL600 from our last series. Yes, it's a LOT of car for the cash. And yes, it has lovely leather seats and televisions and many cylinders. But the engine also blew up. The repair bill? More than a sixth of the car's value. Ambitious. Rubbish.

But Jezza was still making a valid point - there are now some genuine performance bargains out there for the place of a brand-new grey family runaround. Then we heard about this: apparently you can now buy a tuned 385bhp 996-shape 911 for £17,500 with the safety net of a 12,000-mile warranty. Extraordinary car, ordinary money, comforting safety net. Too good to be true?

Not entirely. But more on that later. Firstly, we'd like to tackle the obvious question: "err, how does that work, then?"

The answer's twofold:

1. Something called an intermediate main shaft bearing (pictured).
2. A Porsche specialist in Bicester

So, too good to be true? Yes and no.

For the most part, it feels like a ten-year-old car. The leather's been scuffed thin in places, the displays are resolutely lo-fi and large screens with iThing connectivity and a navigatress are predictably absent.

That's largely because the interior of your donor car doesn't get touched. Nor does the body, suspension, brakes, steering or chassis (unless you ask them to, which would warrant a frank discussion with your bank manager).

But this is not a car for those concerned with equipment. And its builders know it. Instead - for the bargain-bin price at least - they concentrate on the loud metal bit in the boot.

Even on idle, it is very, very loud (it's got the extra £1840 manifold, sports-cat and silencers upgrade, but you can use the originals). It's not sputtery and it doesn't "breathe" like a racer - there's just an innocuous, long drone. The sort of noise Brian Blessed makes between sentences.

But when you pull away from standstill, things change rather quickly. Unlike the inside and out, it positively doesn't feel like a £17,500 car. It's brutishly, incongruously, frighteningly quick. 0-60 takes 5.5 seconds and nobody knows the top speed. "We've not found a road long enough" says Autofarm boss, Josh Sadler.

The sensation of thrust is genuinely unsettling. And decidedly un-Porsche. A 911 usually feels predictable, even rational. This doesn't. It feels barbaric. Borderline offensive.

By the time you hit the 7000rpm limit, you're three inches deeper into the seat than you were at the lights, you've shed everything else from the wheeled world, Blessed's about to gasm in the back and you're coming down with a chronic case of GATSO anxiety.

Dive onto a b-road and the sprung stuff - while noticeably fatigued - does surprisingly well at planting more power than it's designed to on the road. Uprated Michelin Pilot Sports help (though you'll have to pay extra for a set), as do this one's 30mm H&R lowering springs (another extra, albeit a cost-effective one) but the celebrated 911 architecture makes the best of the job.

At ordinary speeds it's just as pliant. Apart from the exhaust's timbre, city driving doesn't give away the potential. There's a slight - and not entirely unpleasant - vibration when the engine's cold and you're idling, but once it's warmed through the spiky cams and general mentalness are perfectly disguised.

This ride's fine but not amazing. Lowering springs give it a bit of extra bounce compared with, say, a showroom 997, but any right-thinking human would expect that from something £50,000 cheaper. And just a second slower to 60mph.

Though it's not all sweetness and light. Yes, it's cheap and profoundly cheerful. But if we wanted to keep it, use it, cart offspring and loved ones around in it and enjoy the power without feeling a bit buttock-clenchy, we'd probably add a few more bits. Like new suspension bushes (£1000), some good quality rubber, like the Michelins fitted to our test mule (£550) and a set of new brake pads (£200) for peace of mind.

So, could you run it for half its warranty and punt it on without losing any cash? Maybe. Resale values are a bit murky as this one's the first of its type, though it should command a far heftier premium than an original car (currently selling from £10,000 to £20,000 in working order).

In terms of running costs, the 996 is actually pretty reasonable. 996's are one of the cheapest proper sports cars to use. The only pricey bits are brake discs (£396 for a pair of fronts, £310 for a set of rears, but you can get old ones reconditioned for £75 a corner). And owing to their propensity to blow up, there are lots of bits around for not a lot of money. Just have a look on eBay.

Consumption isn't too terrifying either - we averaged 31mpg - and insurance is manageable - around £650 if you're over 30, using it as a second car and have a clean license. Though we'd budget £2000 a year for servicing and wear and tear.

So, that lot drags the price up to £19,550. Which is still less than a Ford Focus. And nearly three times more powerful.

Like Jeremy's CLK, this thing is a LOT of car for the money. But the warranty takes the edge off buying and using a cheap, powerful and once-expensive sportscar. But buy one with your eyes wide open. And get shares in Optimax.