well, you most likely have a zetec if it is a bare bones model as you say it is. As far as modifications, you came to the right place. People with non-SVT contours typically install an SVT ground effects kit and get rims as their first modifications. But with a limited budget, that is kinda tough to do. If you want my honest advice, don't modify the car at all, save your money for when you get a newer car when you are done school.
