Once upon a time the Rover K Series went in seemingly every sports car imaginable, from Caterham Seven to Lotus Elise and Ariel Atom to, well, the MG TF. And with good reason: it was a light, revvy, exciting four-cylinder engine, perfectly suited to light, rev-thirsty, exciting cars. Unencumbered by the extra weight of vehicles like the Land Rover Freelander it was also put in, the K Series generally proved less problematic in the smaller roadsters.
So how about this for the ultimate expression of maximum K Series naughtiness with the minimum of motor vehicle to drag along? It's a Westfield FW400, a car that arrived at the end of the 20th century with a focus seemingly on being the most technologically advanced, raw and thrilling Westfield yet made. Quite an aim.
To that end five FW400s were built on a carbon monocoque for the lightest possible weight and greatest possible stiffness; the ad for this one states a 397kg (!) dry weight, along with torsional rigidity way in excess of a regular Seven. This particular car is exceptional in having a carbon body, too, making it the leanest of the lean.
As if that wasn't enough, the previous owner of this FW400 has seen fit to tinker just a little, the aim presumably to make the flippin' fast get somewhere close to utterly feral. The VHPD K Series has been rebuilt, including Jenvey throttle bodies, an Emerald K6 ECU and a bespoke exhaust, meaning peak power of nearly 220hp. It's dry-sumped, too, surely a necessity with something as overtly track biased as this, yet without compromising the integrity of the structure. They've even gone to the effort of using titanium nuts throughout the car, shaving more precious grams.
This is all on top of a base package that included Penske dampers, a Hewland straight cut gearbox, adjustable anti-roll bars and a design penned by former Lotus F1 man Martin Ogilvie - it's quite something. And the all the mods in place are reversible, for those after the original experience. On the other hand, those who might like to compete with their FW400 will be pleased to know that it's being sold with spares - including a different clutch and flywheel - that will make it even more circuit ready.
All of which sounds pretty exciting, does it not? Moreover, despite all this work, the FW400's incredible rarity and very exotic spec, this one is for sale at less than £30,000 - about the same as you'd pay for a Lotus Exige of the same era, or even a retro Caterham Seven from the present day. Doesn't seem a lot of money in that context, does it? Just don't forget to wear your (carbon) helmet as well - that aero screen doesn't look suited to deflecting anything away from your face...