I have just installed a Custom Corbin Seat. It seems to rest dead on the center tupperware part that goes from the front of the seat to the top compartment lock. I do not want to scratch or take a risk of cracking that piece. Should I put a couple of washers or spacers between the seat and the seat mount? Also the OEM back seat back pad isnt flush with the trunk backrest. Is there a way to move the topcase back some? Thanks in advance.