Does anyone make a luggage rack that sits below the rear seat (about even where it would mount)? I noticed all of them seem to sit even with the rear seat and there is a compartment or void about the thickness of the seat under the luggage rack which I would not use. The reason I ask is because I would like to put a low-profile tail bag on the bike for around town, and if the rack were two or three inches below the rear seat that would make the tail bag lower for swinging my leg over it to get on the bike. I did a quick search and did not see what I was looking for. Thanks