A proper mini, although completely redesigned in terms of chassis (with a strong roof!), almost completely built out of carbon fibre/composite. Should look like a normal mini, no daft widening or anything and nice and skinny 12" wheels. (Although need to get better tires from somewhere)
Then, to make it a bit more mad, design and build a two stroke fuel injected V6, very much following motorbike engine design, and either
A. Stick a couple of huge turbo's on it, and design a mega strong CVT gearbox to go with it...
B. Supercharge it and give it a nice 7 speed H gearbox
undecided whether it should be mid engined, or just move the seats back (no lengthened bonnets for me!), and of course it should be AWD.
Or just give me an Aston DB9 / Ferrari 275 / Jaguar XJ13(!!!)