I just know that it wasn't MOTU, but it was probably compatible, and I think I'm even picturing one from one of the toy/Christmas catalogs from which it had an advertisement in! In a way I'm thinking that is was a better suited design for the Attack Trak, and it's gimmick was based on how a tank moves on two tracks, but this vehicle only had one large one as you said, that actually went around the entire cab, correct?
EDIT: OMG I did a little investigating and just found a pic(#14) of it! This is what I was thinking of, is this the one you were thinking of as well?
Trundaxx! It's the awesome remote-controlled vehicle that moves forward and reverse.