If you could distill anger to provide yourself with a supply of 100 per cent proof 'Pissed Off', you'd basically have the opposite of a love potion - a fighting brew more effective than six pints of Stella and a quarter bottle of Teacher's. If you then fed the resultant cocktail to an unwary SLR, you'd end up with this; the Mercedes-Benz McLaren SLR 722 GT. A car that looks as comforting as a broken bottle swung at your face.

Before we immerse ourselves in the detail of this specific evolution, it's worth knowing a bit about the SLR history. There was a story doing the rounds when McLaren originally got involved with Mercedes to build the SLR, things got a bit fraught over what each company thought might be the ideal specification.

McLaren apparently wanted purity and function, Mercedes the kind of car it could sell to expect-it-all rich people without having to justify enormous compromise.

It was aircon versus aerodynamics, ultimate speed versus long-distance driveability, focus versus the finer things. Neither won the argument conclusively, which is why the SLR is a little of both and all of neither. It ended up being a fabulous car that has the emotional cracks of an identity crisis peeping through the leather-clad carbon fibre. Which is why, in the bar fight of the universe, the regular SLR might be construed as something of a pearl-handled revolver - effective, but unnecessarily garnished.

As the 722 it became more of a Saturday night special and in 722 GT form it has reverted to something more akin to a Stanley knife blade gaffer-taped to a fist-sized piece of wood. This car is pared back to slice'n'dice efficiency, all the frippery burned away so that it requires you to get up close and personal. As they say: guns for show, knives for a pro.

So what is the 722 GT? Well, this is a GT racer for those people who want to attack a circuit in a GT version of the SLR and not have to worry about driving it home afterwards.

The GT has been designed as a 'pure super-sports car' by British motorsports specialists Ray Mallock Limited (RML), has no approval for road use and will only take part in the SLR Club Trophy - a kind of SLR one-make series for the heinously rich run by the SLR Club.

At the moment there are only plans for 21 examples, and all have had a pretty thorough re-working from the Northamptonshire-based racing outfit.