Just got my first mobile rig - an Icom ID-5100 dual band. I'm planning to mount the radio body under the passenger seat and run the control head up to the dashboard. My main concerns are proper power wiring (should I go directly to the battery with an inline fuse?) and antenna grounding. The antenna mount will be on a painted luggage rack - do I need to scrape off the paint or run a separate ground wire? Any installation tips from experienced mobile operators would be appreciated!

Don't just look at the power output of the radio - focus on the ERP (Effective Radiated Power) of the system, which is computed by multiplying the power output by the antenna gain. For power, yes, run direct to battery with proper fusing. Do not confuse DC grounding which is best done at the radio with RF grounding which needs to be done at the feed point - you want the car body to be the ground plane.

If the paint interferes with grounding, you'll need to scrape a bit of the paint or powder coating off. You can also run a short grounding strap from the mount to a grounded part of the vehicle, but keep the strap as short as possible. Test your SWR before permanent installation!

Great choice on the ID-5100! A detachable control head allows the bulk of the radio chassis to reside out of sight, with power leads routed through the firewall to the car battery and coaxial cable routed out to the antenna attachment locations. Make sure you use proper gauge wire for the power runs and consider ferrite cores on all cables to minimize RFI.