I did this some time ago for plugging in the truck. Instead of having a cord hanging out, I went to Kenworth and got a block heater recepticle for a semi, and drilled the fender by the logo and that where I plug the block heater in. After drilling I used touch up paint and some silicone sealer to prevent rust. So much nicer than the old way... Now I just flip up the cap and plug it in... I even etched off the Kenworth logo and took the Dodge logo off a keyfob and glued it in place...

 

got any pic's of it?