A question for any dealers out there....

I bought my Fab vRS on the 'New Solutions' HP type thing, my question is this: What (if any) modifications would be allowed given that, as I understand it, it's not really my car until the end of the 3 years and the final payment (at which point I'll likely be wanting a new one anyway!).

Specifically I'm already working on mounting an iPod (shouldn't be any permanent changes there) and am wondering about eibach springs and the SEAT front brace, oh and the elegance cup-holder perhaps!

I'd love a bit of engine tweaking but then, as one of my reasons for buying the car in the first place was the economy that'd probably be a bad idea