[Vwdiesel] 2 way radio antenna placement

[Val Christian]

I'm wondering if anyone can comment on 2 way radio antenna placement
on a TDI.  I have an '03 Jetta TDI, which lacks installed ham radio
equipment.  I'd like to install a dual-band radio 2m (146mHz) and
70cm (445mHz), and a permanently mounted antenna.  I'm considering placing
a 2m 1/4 wave antenna in the center of the roof.  When ECUs started
coming out on cars I recall problems that people had with the placement
of antennas, and their effects on the operation of the engine.
Can anyone comment on the sensitivity of VW equipement to RFI?

My intended power would be on the order of 50W.

I'm also concerned about high RF levels on the "Monsoon" radio.  Not
so much in desense, as I expect that.  Rather, I'm concerned with
front end damage, as the antenna is roof mounted near the center by
the back window.

My 91 Jetta has a through the glass mount, on the back window.  The
AM/FM broadcast radio antenna is on the left fender.  Little desense.
The through the glass mount (Larsen KG2/70) performs well.  Unfortunately,
similar placement on the 03 would have it immediately adjacent to the
broadcast antenna.  The 91 Jetta lacks any kind of an ECU.

Thanks for any authoritative or anecdotal information you can pass on.

Val