incubusjohnny

I will be installing the Basslink II into my trunk and wanted to mount it directly behind the rear seats right up against them. I am concerned that if i were to mount it here i could hit the gas tank which is right there (drill the screws downward). Anyone know if this would be the case or how much clearance I have there? Anyone who has mounted any sort of sub box enclosure there or a basslink please help. thanks in advance