Big engine, low price, bulging comic-book looks. The recipe for a muscle car has always been a simple one - make it fast, make it cheap-ish, and don't worry too much about sophisticated handling or hi-tech engine trickery.
It's a simple yet appealing formula - the burger-and-fries of performance motoring - and was a spectacular success for US manufacturers in the 1960s and early 1970s. Until 1973 that is, when the oil crisis and emissions controls turned some of the greatest names in American motoring - Camaro, Mustang, Charger, Challenger, GTO - into limp shadows of their former selves.
But muscle cars have made a bit of a resurgence of late, inspired largely by the success of the 2004 Mustang (we'll forget the commercial flop that was the attempt to create a new-era Pontiac GTO based on the Holden Monaro). Now Charger, Challenger, Mustang and Camaro once again duke it out on US streets and in the showroom.
Next year the re-born Camaro (200,000 sales so far and counting) is coming to the UK as an official import in top-spec 426bhp SS guise. So when Chevrolet asked if we wanted to borrow one for the evening, we thought it would be rude to decline. Just to keep the Chevy honest, we also asked Ford if they wouldn't mind us borrowing their 540bhp MY 2010 Shelby Mustang GT500 - king of the current crop of muscle (in performance terms at least) - for a spot of comparison...
The Chevrolet Camaro certainly gets the visuals right - both inside and out. On the outside, every bright yellow curve bulges and twists in a way that leaves you in no doubt that this is a powerful car - it just would not be possible to design a car like this and then put a 120bhp 1.6 beneath its bonnet.
The Camaro's huge presence is almost certainly as much to do with its sheer size - and this particular car's Transformers yellow-and-black Bumblebee livery - as it is down to the creases and curves of its actual shape, but there is no denying that the big Chevy is an almost unreal sight on British roads.
The cabin is so often a poorly designed, plasticky let-down in American cars that we weren't expecting a great deal from the Camaro, but the Chevy's cabin is a bit of a revelation. Okay, so the quality of its fit and finish would be disappointing in an Audi or BMW, but the general feel and design of it is spot-on.
The chairs are comfy in that squashy way that only US luxury car seats seem to manage, while all the electrical gismos you could want are present - including a head-up display nabbed from the Corvette. What really sets the Camaro's interior apart, however, is that it carries on the muscle-cum-concept flavour from the exterior. This is a car that reminds you it is special, outlandish and just a little bit ridiculous from the driver's seat without you having to catch a glimpse of it in a shop-front window.
So the Camaro manages a convincing update of the muscle car formula outside and in, and with a 426bhp 6.2-litre LS3 V8 beneath the bonnet it has all the shove you would want of a muscle car. Fortunately, thanks to a chassis that comes from the Holden Commodore - aka the Vauxhall VXR8 - the Camaro handles in a most un-muscle-like way.
Even when it heads over here officially next year the Camaro will come with a US-spec suspension set-up. Officially imported cars will therefore feel, much as this one does, a little softer and less incisive than a VXR8 over a challenging road. You can still tell that the Camaro has a 'proper' chassis underpinning it, though - the MacPherson strut/multi-link suspension endows the Camaro with an innate balance and dynamic sophistication that - as we'll see later - is rather notable by its absence in the Mustang.
Curiously, however, sheer size is much more of an issue for a Camaro than it is in a VXR8 - despite the two sharing broadly similar footprints. But while a VXR8 shrinks around you to a surprising degree, the high waistline and long, bluff bonnet of the Camaro, combined with a low seating position, makes it hard to position the car to avoid low walls, kerbs, gutters and even - it feels like - small children and dogs.
Still, provided you don't live down some narrow lanes - or don't mind picking terrier out of the grille on a regular basis - and fancy a spot of brash US beef, the Camaro has a hell of a lot going for it. The fact that it handles, and is expected to pitch up in Blighty for a reasonable £40k, makes it even more appealing.
The Mustang is somewhat more old-fashioned than the Camaro. Despite a pretty epic 540bhp and 510lb ft courtesy of a supercharged 5.4-litre V8 (superseded for the 2011 model year by an all-new motor), it still makes do with a live rear axle.
From those few nuggets of information you may safely infer that the GT500 is a muscle car more of the make-it-fast-in-a-straight-line-and-sod-the-corners variety. Which, provided that's what you're looking for, makes the GT500 very entertaining indeed.
The straight-line performance is certainly impressive, with the big-hearted motor providing a wall of seamless, supercharged acceleration throughout the rev range. The sound is nice, too, a classic V8 grumble overlaid with an insistent - but not intrusive - supercharger scream.
There is a caveat here, though, because the GT500 is only fast
when you can get the power down
. Which means that as soon as a road gets damp or even too bumpy you can forget flat-chat acceleration. A far less powerful car with a more intelligently suspended chassis would soon leave the Mustang for dead on a bumpy road. There's plenty of grip, but bumps unsettle the car too easily, and the steering is quite vague - finesse is not a word you would associate with the Mustang's dynamic behaviour.
The gearchange is lovely, however; with just the sort of chunky, precise throw that a car as meaty as this should have.
Finesse is also not a word you would associate with the Mustang's interior. The GT500's cabin looks the part, but only if you squint and don't touch anything, because it is appallingly finished by European standards, although the 'Shaker' stereo system does sound good.
But wobbly cabin standards and 'traditional' handling shouldn't matter too much if you buy into the muscle car thing - because the GT500 oozes presence, makes some cracking noises and goes cheek-squashingly quickly in a straight line. But you will have to be prepared to make some sacrifices for your muscle, because by the time you've imported a GT500 into the UK, you'll be looking at around £46k. And that's edging rapidly towards M3 money...