It's fun enough as it is! I have mine painted in Reflex Purple, slammed to the ground and fully tuned... I love it. Same goes for my 500, Kübelwagen and VW Samba Bus... Whoever still can't get over their premium status needs to tune them first THEN say they don't like them.
That said, a unique pond circuit would be awesome, like the Pod race from GT Concept; the really short circuit with huge ramps and such that you could only drive in the Pod (I can't remember who designed it, Nissan or Toyota maybe?), something similar but bigger would be pretty fun. I had to edit my post to say that after watching the video.
