The car looks great, I reckon you have done a good job with it.
One thing i wanted to point out was you have mounted the amp upside down on the boot lid.
My understanding is amps need to be mounted upright or or sideways, but mounting them upside down can cause them to cook themselves, because the heat instead of travelling up the headsinks and being disperted in the air, they travel up into the circuit board and cook the componets.
Steve