This is a question for those of you more technically inclined than I
am. I plan to install a Kenwood dual band mobile in my 2003 4Runner.
I am considering two options for the installation and would like to
get some opinions on which option would minimize the chance for RFI
interference/damage to the onboard electronics.

In all options the antenna will mounted near the rear of the car using
a Comet lip mount.

Option 1 – Put main unit under the front driver's seat. This would
allow for the shortest power cord and should allow me to mount the
control head and mike without any extensions to the standard cord.
The antenna coax would run to the rear. My concerns are that there
is a wiring harness under the seat that has sensor for seat position
(controls air bag force). There is also wiring for power seat
functions. The main unit would be less than an inch or two from that
wiring harness although I could keep the antenna cable away from this
area. (This is my preferred option from an ease of installation
standpoint)

Option 2 – Mount the main unit in the rear cargo area. The antenna
cable would be much shorter but I'd have to run a power cable, mic
cable, speaker cables, control head cable, and GPS cable from the rear
to the front of the vehicle, probably under the carpet. All of these
cables would have to be extended. This would be a harder install.
There is also the risk that I could bump the unit when loading cargo
and it would also be visible to anyone looking into the car.

I've read Toyota's guidelines which have been posted in several
different notes recently and their major concern as far as the
installation location seems to be keeping the antenna cable at least 8
inches from ECUs and wiring.

Option 2 seems to be the safer choice but am I being overly cautions
by ruling out an under the seat installation.

Regards,
KC7GDA