That's what I followed to put mine in. My cobra unit is a bigger box unit so I just screwed it onto the top of the radio console (there is another writeup on installing the cobra 29 wx bt on the project JK forum about this) instead of mounting it overhead. It is super solid offroad and doesn't move around/rattle at all. I also found that I needed every mm of length with an 18 ' coax to weave it through the dash, and to the my tailgate. It wouldn't be an issue with a non-unlimited jk though. I was also a little restricted by the height of my work parkade and instead of using the teraflex spare mount bracket (which with a 3' antenna was about 2-3 too high), I just went to home depot and bought some Stanley 90 degree chair brackets and Dremeled it to fit in the recess of one of the bolts that holds the spare tire on. The bonus was that it cost me all of about 2 bucks. I used a 14 gauge ground wire and it works wonderfully. It is about 3 inches lower this way. I'm running the flexi Wilson 3' antenna on it and the reception is crystal clear. Sure, the alternative would have been to use a longer whip and tie it down all of the time, but I'm into solutions that I don't need to always change when I want to go wheeleing
. If anyone needs help with this, pm me and I'd be happy to help.
J.