I have done far too many to just choose 3.

And I am Still adding More.

 

1 Blackout reflectors(turns signals, brakes, markers and those stupid little reflectors on the back that are not lit).
2 Exhaust (header/dp/port and polished exhaust manifold and high flow muffler.
3 Rear camera, 5% tint plus factory gets a little hard to see where you are going in reverse. Also the rearview is worthless going down the road with the stereo over 1/4.