I don't think the motive was to rob TM/MS of the car, even though that's why he was arrested (and what he inevitably did). The reason I think this is twofold;
1) Why bother? The car wasn't worth what a pair/few pairs of shoes could bring in, and CD was driving a much nicer vehicle already.
2) I think this likely has more to do with all of them knowing DF, whose whereabouts are unknown during the time plate readers caught the cars headed back to the farm. Where was DF during that time? He went missing the same night, and who picked him up? Was it indeed CD? Was he in the truck with CD? Or any chance he was the one driving TM's car?
It's easy to say "maybe he lured them to the farm to sell the car" but I don't think it's going to be that straightforward. MOO, it just doesn't make as much sense to me as it should. And yeah, this is all my opinion.