first off, think about it, performance upgrades, increasing horsepower, etc, all decreases fuel economy, and i'm sorry but four inch wide exhaust pipes look ridiculous on a car of that age, a spoiler wont do anything for that car either. if its in decent shape and you want to drive it for a while, beef up the suspension, sway bars strut braces, find some rims you like, maybe new springs, and stiffer shocks, but just remember, it might not be a good idea to lower the car if you get a decent amount of snow on the road in the winter, you will get stuck much easier in less snow if the car is 2" lower. Another thing to remember is when your car is that old, there are other things that are more important, like timing belts, and suspension control arms and cv axles, things that could leave you stranded, or ruin your engine are the sort of repairs that would best be taken care of especially if you want to make the car faster. If you drive the car harder, the parts take a much bigger beating than in regular driving