I have a Sprinter Van, a GMRS radio and a VHF/UHF radio. Currently there is an NMO mount on the roof for the GMRS. I want to install my VHF/UHF in the van as well but don't want to drill/run another cable to the roof. So... I can mount either of the radios under the dash and a new second antenna on the hood hinge. My question is... Which one would lose the least performance mounted on the hood? The one advantage of the GMRS on the roof is that I am running one of the short 6" antennas up there and there is minimal increase in vehicle height. At a minimum a VHF/UHF up there would add 15", but on the hood the top of it would likely stay well below the roof line. Thanks!!