No you can't put an 18 on a 19 inch rim. Either get a set that are staggered like the stock or you are going to have to get all new tires to match your rim size. I got $500 for my set of rims which were in 95% perfect condition. I'd stick with 19's in the rear and 18's up front or go up a size, just remember if you do that you will need tires of the same size to fit the wheels. Part of the beauty of this car is the staggered wheel look. Check my gallery I have almost the same wheels on my car and they are 19's in the rear and 18's up front.