There is a shop here in Salem, OR that builds some very nice brackets, vehicle specific, quarter inch polished aluminum. Drilled for 3/8, NMO, UHF or whatever and made to conform to bed so they clear fiberglass tonneau covers or canopies. Setup for ground strap and useable for either side of the vehicle. Has made some that come out of the back of hatch back rigs too. Not cheap but if you want something that really does a great job. If you are interested shoot me an email and I'll send a picture and contact info.