I mounted my antenna to my spare tire carrier then put a grounding strap from the inside of the tailgate to the inside of the tub. I have a 4' antenna which sticks up at least a foot above my hard top. My range is roughly 20 miles. I know this because I've sat in my driveway, heard activity on the radio and communicated with the transmitter, verifying his/her location. The farthest I've gotten is 22.5 miles as the crow flies.
1995 Blue YJ i-4 AX-5 33" Cepek Crushers on 2.5" Rancho lift - SOLD October 2010
1996 White ZJ i-6 auto bone stock
1987 Maroon YJ i-6 Auto (1.5" body lift. OME 2 1/2" lift. Rancho RS5000 shocks. Rancho steering stabilizer. A-Z Fabrication rock slides. More upgrades coming soon - LOL)