Almost leased an FR-S

[import_nation]

Modifying lease cars is ok or not depending on the dealer. I've seen people do big modifications to a lease car and just return it to stock when they return the car.

[BODHI85]

I don't think upgrade with TRD performance parts will break the lease contract. Dealerships are different in regards to installing TRD parts. The dealership near where I work told me that TRD parts have to be bought and installed by Scion techs in order for warranty NOT to be voided.

General rule of thumb. Don't do anything that can't be be easily undone. Try not to mess around with the engine too much.