There must be something in the water in this part - my part - of sleepy, rural East Sussex. Petrol, probably.

On a farm near the village of Buxted you'll find historic motorsport specialists Crosthwaite and Gardiner, who can build you, from raw lumps of aluminium, a sixteen-cylinder 1930s Auto Union racer. Or rather, they can build you one if you're Audi - which has commissioned seven - because only a global carmaker could handle the bill.

By coincidence, at another hobbity farm nearby you'll find Eagle, whose work on E-types just as astonishing and almost as expensive. The exact location isn't made public, given the value of what you'll find here, but if you seem like a serious prospect you'll be sent directions, which include helicopter landing coordinates. I drove there.

Eagle and Jaguar E-types: a match made in heaven

Eagle was founded in 1982 by Henry Pearman. Henry knows a fair bit about Jaguar E-types. He will sell you a standard car, but only if it is one of the very best. Don't expect to find much on his stock list under £100,000, and standard road-going Es with an interesting history can nudge £300,000 now. He will restore your E-Type, but only if you commit to having every last nut done: ‘we're not interested in half-doing things’.

Or he will build you an Eagle E-Type, which is a standard-looking car with a bunch of 'enhancements' refined over 20 years and including AP Racing brakes, Ohlins suspension, power steering, air-conditioning and electricals that actually work, unlike most that came out of this country in the sixties. Prices for these Eagle E-Types start at £300,000, plus the donor car, plus options. Each takes around 4000 hours to make.

And then there's this. The Low Drag GT. Now, we're talking truly Leno-esque levels of automotive indulgence. So far, just one exists; it's just been completed, and I've driven it. 'Just a few' will be made - probably no more than six - and you'll need at least £700,000 to buy one.

£700,000 for an E-Type? Really?

Eagle sits at the nexus of two trends in the classic car world. First, the reappraisal of the E-type, which even Enzo famously described as the most beautiful he'd ever seen, and which many drivers and racers preferred to period Ferraris, yet which have always traded for a fraction of the value of their Ferrari rivals. Greater supply alone doesn't explain their cheapness, and it's now being corrected.

The second trend is the whole classic-reimagined, better-than-it-ever-was movement typified by Singer Porsches, and the rest. Each takes a genuinely iconic classic and irreverently improves it, either starting with an original shell or an entirely new chassis, and freely using whatever it takes to make a car that drives as well as it looks.

Eagle's Low Drag GT uses a donor car, still carries its VIN plate, and reuses as many of its components as possible without compromising the end result, which at this price needs to be perfection. The bodywork is hand-formed from aluminium and features lower sills (with a lower seating position) and a wider track, which sort out the only two criticisms you ever hear of aerodynamicist Malcolm Sayer's original shape.

The upper body is a direct recreation of his original, one-off Low Drag Coupe, which he built in advance of the E-Type's launch as a prototype race version, but which regulation changes and Sir William Lyons' loss of interest in racing meant was never pursued. That one car - CUT7 - still races, and really does rival those Ferraris for value.

Eagle Low Drag GT: the oily bits

Into this body goes everything Eagle has developed for the E-type: its bored-out 4.7-litre development of the XK straight-six, here using fuel injection like the later Lightweight E-type racers, and with an aluminium engine block (made by the neighbours) to cut mass. There's a five-speed gearbox (again like the Lightweights, but here with an ally casing) and the E's Power Lock diff, again in a new ally housing.

The brakes are four-pot AP Racing items, 315mm at the front. There are eye-wateringly expensive Ohlins adjustable shocks and lightweight magnesium wheels. With a mass of just 1038kgs and around 345bhp and 360lb-ft from that engine, the Low Drag has an age-appropriate amount of power, but a better power-to-weight ratio than a modern Jaguar F-Type V8 S.

Much of the engineering has been carried over from the Eagle Speedster, a run of six roofless Es which all sold, despite a £600,000 pricetag. In making the Speedster, Eagle's Technical Director Paul Brace was brave to attempt to improve on the looks of a car in the design collection of New York's Museum of Modern Art. But armed only with hammer and power tools, he managed it.

Using the original E-type's architecture, subtly integrating the new switches and dials, and trimmed in blue leather, I think it's the most beautiful cockpit I've ever sat in, and is a crushing reminder that I'm just not rich enough. If you are, you can of course have the cabin, and the entire car, anyway you like. One customer wanted the Jaguar 'growler' at the center of his Speedster's hornpush to look a bit growlier, and Eagle was happy to oblige.

Does the Eagle Low Drag still drive like an E-type?

Yes and no: it certainly drives like the two Speedsters - one-third of total production! - I have been lucky enough to drive too. With that power-to-weight ratio, Eagle's claimed sub-5-second 0-60 time feels modest, the Low Drag generating chest-tightening thrust when you sink the throttle, accompanied by a deeper, louder, richer remix of the XK's hallmark trombone exhaust note.

The 'box changes with a similar weight and throw to the later E-Type’s synchromesh four-speeders but is quicker and sweeter, though the emphasis on torque means you can often dispatch slower-moving moderns without changing down. The ride isn't as fluid as a standard E's but you trade it for a greater connectedness with the road through backside and fingertips, and you can have it set up any way you want.

There's more grip, yet not too much. With 225-section front tyres and 235s at the back it's not over-tyred like a modern of the same power, and retains the drifty throttle-adjustability that ought to mark a sixties sports car.

Like a Lamborghini Miura, the joy of driving it comes as much from the knowledge that you're piloting that extraordinary shape through the scenery; you feel like you're performing a public service. You're more inclined to stretch the Speedster knowing that you have functioning brakes when you need to restrain it. Instead, the main brake on your progress along these wet, narrow Sussex lanes is that 7000 man-hour figure, and the fact that this is the only one, and it's got an owner waiting. And you wouldn’t want to be remembered as the man who fell through the Mona Lisa.

Verdict

But what about this whole better-than-new movement? Should Eagle be 'enhancing' one of the great cars? Pearman is unapologetic. He sees no conflict in improving on cars he loves, yet cheerfully admits were often badly made. 

"You wouldn't live in a beautiful Georgian house and still chuck your sewage out of the window," he says. "Having a classic car with brakes that work and that won't overheat and that will take you to the south of France and not disappoint you is a good thing. We know E-types. We stay true to the spirit and heart of the car. We just make them work."