Well I had 20 on the 3 rear windows, and 35 on the two front windows, and it was ok, but at times I didnt think it looked that good. The good thing about it is that 35 is so light compared to 20, that the cops usually dont say anything about have 35 on your front side windows. I would say go for 35 all around, just to steer clear of trouble. That what I'm going to do on my new teg. My car is also black, so 20 all around would just be too dark. But yeah, go for 35 all around.