Not wanting to hijack the current Smart car discussion elsewhere...
Saw this when in Paris a few months ago for my honeymoon, and managed to snap a few pics:
It is a Brabus Smart, which is essentially the Smart we all know, that has been given a bit of get up and go.
They do this by mating together two standard 3 cylinder Smart engines, to make up a single V6, as well as by doing a couple of handling mods.
For less money than the V6 option Brabus will kit you out with only the handling pack, and a "chipped" version of the original.
From what I saw, the V6 seem to be more than just a bit quicker than the standard model, though I am not sure if I would trade my p-car just yet.
A couple of roadtest (unfortunately none of the V6 I think) are available on Youtube, for your entertainment:
http://www.youtube.com/watch?v=CxJaGG1CobI
http://www.youtube.com/watch?v=5GKIxtxwt2A
http://video.google.com/videoplay?docid=4334889674322589612