Yeah, if it's cheap, it wouldn't work. For example, molded plastic hex bolts wouldn't cut it. I guess the actual filler tube is so deep in there you actually need that large diameter, too, so you probably don't want to steal any size.Might look ok on the audi but would probably look like it's from pep boys or AutoZone on the Z. The gas filler lid is so oversized already you probably don't want to bring any more attention to it imo