I got this as a gift one year. Had no clue what I was gonna use it for. Ends up being my favorite tool. Handle rotates on bearings, adjustable height, and is removable. Keep it with a 10mm socket and leave it under my cargo tray. Amongst its several uses, I have also used it to disassemble the dash so I could fix the fuse in an aftermarket stereo in my 4th gen all while sitting in traffic.
10mm socket is probably the best thing to keep handy. Not sure I would use the tool Mutant posted while driving but hey whatever gets the job done eh.