I changed my wheels/tires and have a 5th matching full size for use as a spare. These wheels will be in a 5 tire rotation to keep wear even. Unfortunately this is a slight issue in storing the spare as it is much thicker than the factory donut. I have it in for now, but I need to do a few minor mods for it to fit well. I need some way to bolt it down so it isn't bumping around back there. I am thinking of some sort of hook that bolts down in the factory hole. Thoughts? Next, I need some form of filler for the space below the rear mat (like the factory foam inserts that are now too short). Any suggestions or ideas?