Hardest mod I have done I think would be the cupholder... Not that it was "hard" to do but it was very time consuming and ran into many problems along the way.

Best would be having Paul and Rudy install the V8. Brings a smile to my face every time it starts up.

All the other mods that I have done and some that were here and gone all have their little quirks but well worth the effort. Its the little things that I personally like that go un noticed which make my car special.