That think is pretty sick and a perfect example of a death trap.
I don't think there's much left of the smart car other than a couple of panels. Looks like a custom tubular chassis, it's a 'busa engine, etc. Still pretty fuckin sweet though, it'd be fun to do up a sleeper that looks stock but has a hayabusa engine in it and smoke guys off the line! :P I used to do that in a rusted-out turboed Miata all the time.
That looks fun as hell! If you could go more sleeper and have the two seats still it would be cooler. How much fun would it be to pull up to a light and smoke a Mustangs ass! See a bunch of WTF faces!