Recontent the interior door handle lights with LEDs (if you don't have the lights already). Pollo_Loco69 and I have this done on our cars. We will be taking pics and doing a write up as soon as we do his Dad's Contour.
There are some pics in the Pics and Videos section and in the Utah section.
Other then that, I will add:
-Intake
-Exhaust
-Stereo System
-Car Alarm to protect goodies.