Save your money, and wait a a couple of years until you're 21, then with the money you've saved, and not spent on badges, trim, seat belts, wheels, and other parts to make the car look like an UT, you'll be able to spend on a better and newer fast car. (Punto GT? Punto HGT? etc).
I speak from experience, and when I was 16, and spent all my hard earned cash on making my Fiat 127 look like the 1300GT model, and then had no money left when I wanted to by my next car, I regretted it seriously. So I spent no money (except for servicing and fuel) for one more year, and then had enough to by an Uno Turbo. Money much better spent.
In any case, adding bigger wheels, more trim, etc, etc will only weigh the car down more, which will make you're 1.0 feel even slower than before.
