Maybe some help for others
Lessons learned. Don't mount Autocom under the seat. Makes the microphone lead WAY too long and susceptible to RF pickup from the antenna. I got it to work but had to use 6 RF chokes on the mic line to damp out the radiated RF. Worked pretty well after that. Still need to find out how/where the ignition noise is leaking in. It's not bad but would like to improve.
Worked pretty well on the 30th annual bike trip. 2500 miles of gorgeous CA/OR twisties and the occasional adult beverage