It seems I am unable to replace my cars batteries. Is this a glitch, or am I just doing something wrong? I was under the impression that all you needed to do was "use" the hood of the car, but it is not differentiated from the cab, so all he does is try to use the car, which obviously doesn't work.

Yeah, that did it. Thanks.
Thats an annoying way of handling recharging.

I wasn't sure exactly, it was something I believe I read in one of the readme's for the unofficial patches as being listed under 1.1 fixes.