I have a 2007 Gulf Stream RV built on a 2006 Mercedes Sprinter chasis. I bought it new but the dealer seems clueless regarding details of the vehicle. There is a box or more to say a bracket secured to the floor behind the driver's seat with a nylon buckled strap, as if something should be secured to it. I haven't been able to find out what belongs there. Any ideas? When I bought the MH it didn't have a spare tire; dealer said it didn't come with one. However; it had a bracket behind the rear axle and I added the tire. But what about the box?