it all depends on what you want with your car.
if its speed, i suggest you save it and wait until you have enough money for a faster setup (turbo, swap)
if its looks your going for, spend it on a full detail (nothing is nicer then a freshly detailed car)
if its luxury your going for, spend it on a nice little audio system
if you dont have it already, get a nice alarm system.
or just do a tune up :]
if its speed, i suggest you save it and wait until you have enough money for a faster setup (turbo, swap)
if its looks your going for, spend it on a full detail (nothing is nicer then a freshly detailed car)
if its luxury your going for, spend it on a nice little audio system
if you dont have it already, get a nice alarm system.
or just do a tune up :]