[k9kuz]

Purchased Diamond 770, dual band, fold over, today. Also picked up a permanent mount (in roof next to existing antenna) for it. Two pair power leads, fused, have been run from battery to center console. Considering options for HF antenna: roof ridges prevent mag mount, rails too thick for u-bolt type mounts.
I have been running vhf/uhf with a mag mount for the short term and no RF problems.
V6/AWD now with 3K miles: 17 mpg city usually and 24-26 mpg hiway at 65.

 

[RVHAM]

I would consider some separation between the multi-purpose antenna on the roof and any transmitting antenna. This would help prevent overload of the vehicle's receiver front end circuits.

My installation is a VHF/UHF ICOM IC-208H with Maldol EX-107B mounted on an L bracket next to the hood. No EMI noted to the vehicle systems. GM has done a good job at sheilding their electonic systems from EMI.

 

[k9kuz]

I've been using a Diamond fold-over dual-bander on a mag mount about 1 foot from the car's antenna with no problems, even at 50W. Just purchased a permanent body mount for that same spot. Now to find a mounting system for some sort of HF antenna...... without breaking the bank.