That would be awesome. I can see it now: He stops by, late at night, in search of a part because he's got places to be and one of the garages in town told him ol' Bobby Singer keeps really odd hours. But then there's crashing and nosies and cursing, and he runs in...to find Bobby in the middle of some really strange-looking ritual or something, and the he'd be all, "What the hell is going on here?" and Bobby would be all "Balls!" and distracted, and then the monster would jump them and there would be epic fighting.