Question on insulating

Ok all quick question about insulating the top! I've several people on here when they use foam board insulation they cut grooves for the wires, On mine I will beusing foam board on the bottom and insulation from a/c duct tubing on top of it,should I groove the foam and not cover the wires with the other stuff, or will they be oksince the stuff is not heavy? Just making sure their is no danger from something on the 12V wires and batthery wires.
Cliff
Cliff
