what kind of car? Is there anything metal underneath the rear bumper you can attach a metal plate to? I would just get a trunk lip mount and a francis antenna and call it a day. http://www.wearecb.com/store/cobra-a...it-p-1090.html If you are concerned about your car don't get a mag mount. It will scratch it. NMO mount isn't a bad idea either. You have to drill a hole, but its a lot better. http://cgi.ebay.com/Larsen-27-31-MHz...428132012r7903