I don't know if its just me but everytime I look at the rear I notice some tuck in the rear end. Anybody know what size spacers to put for a 'flush' look or close to it?

 

You can only go with maybe a 3 to 5 mm spacer before the wheels will not be hub centric. You will also need longer lugs if you run a spacer. A small spacer would not hurt the car but I don't know whether it is enough to even make a difference.