My G35C is leased, and here is what I did to it: 15% tint on rear windshield, Motorola hands-free integrated car kit, Whistler remote install radar detector. That's pretty much it, the only other thing I am considering is the Catz Zeta fog light system or the Hell Micro DE Xenon driving lights like "anonymous" did on this board. I only have my car for 3 years. I think anything more, such as air intake or exhaust or rims, just isn't worth it for me, personally. I love this car the way it is and I know that once the lease of the car is over, those parts have no value at all (you either have to take them off and do whatever with them, or just give the car back the way it is). You have to decide whether modding your car is worth it for you, personally. But I can tell you that modding a car is a lot of fun...I modded my Jetta quite a bit (rims, short shift kit, air intake, exhaust, tints, shift ****, etc.) so I put a lot of $$$ into it. Even though I knew I had to return it after 3 years, I enjoyed all the mods every time I drove the car and even though they would be worth nothing after the lease is over, it was still worth it for me at that time because I used the mods and appreciated them. But the G is a much more expensive car that has much more expensive mods, so it just isn't worth it for me, personally, to mod my G that much. =)