In the quest to have more space for road trips, I am considering the purchase of this bag that apparently fits over the back of the roadster driver seat: http://www.amazon.com/Roadtrip-Luggage-EUR-Roadster-Seatback/dp/B008HSLE34 To date, I have just stuffed a hanging bag behind the drivers seat and that seems to somewhat work. For the driver's seat position I use, I have four inches behind the seat so it appears that this bag might work since its description says it needs three inches. Has anyone tried this bag in the roadster? I would feel better about ordering it if I knew someone had already tried it and found it works well with the roadster. Thanks.