FT-8800R vs FT-8900R
Remember that 10M & 6M will require different antennas. How many antenna are you going to run on your Jeep?
I ran a Tri-Band Kenwood radio (TM-742) with a 6/2/440 tri-band antenna for awhile in my truck. I'm not sure if anyone make a four band. The tri-band antenna is longer, but I don't think it works as well as the normal 2/440 antennas.
I dual band I have for the Jeep sticks up just high enough and does not hit anything. I think that tri-band might. I did not hear much on 6m FM hear in the DFW area either. If the 8900 is a lot more, I'm not sure if it would be worth it for what you get.
Did you read any reviews on them on EHAM?
KA5IVR ~ 2006 Rubicon, Flame Red, Hanson Bumpers, Warn 9.5ti, and a lot of other $$$ sucking items...