Use autobody adhesive to mount some steel or aluminum tubing to the bottom of the roof, then attach your mounting kit to that. Autobody adhesive is the stuff that they use to attach door hinges and other parts on new vehicles, so it's mighty strong.


1946 GMC Pickup - S-10 Frame, 455 Buick, TH400, original patina.

My 46 GMC on Photobucket