Just got a diamond 8900 and mounted it between my spare tire and tailgate on a bolt on mount. I had to drill out the mount a little bit, as well as drill 4 holes for the PL-259 flush mount connector, so it has a good ground. I confirmed it with a multimeter that it is grounded well. I tuned the 6m band first, as per the instructions, however i discovered that at the VHF band, my VSWR at 144MHz was 2.2:1 and at 148MHz was 3:1. Now i adjusted the tuning and got that VSWR to move slightly down but i ran out of room to shorten the antenna. It improved a little bit but I'm not sure how to get that VSWR down at VHF. All of the other bands sweep pretty well. I am using a Copper Mountain LNA to sweep.