Currently in my 85 with the vinyl rear seat and only lap belts, I drive both kids all over. What I do is pull the belt all the way to the stop, thread it thru the seat and buckle, then I retract it into the reel. On mine, the lock feature keeps it from coming out so I kneel on the seat to really squish it in there while pushing the belt in to get another click or two. Had no problems yet!