I want to do a K5 install on a 2021 BMW R18 First Edition.
Anyone have any suggestions or warnings about dealing with a BMW. The BMW brand is new bike to me. I have many years on Honda and that I'm comfortable with. My concerns are the electronics on the R18 and voiding the warranty.
Cheer
William

Congratulations on your new BMW
I mounted the K2 myself when I bought my new K1600GT in 2018. This has now been replaced by the K3 and also the K5. I've never had any problems with this from BMW. Maintenance is done by an official BMW dealer. I also have no problems with the Canbus system. You don't need the ezCan (in my case). This will therefore apply to several BMW models. I did not have to 'damage' any cable to connect the yellow wire.
As long as you don't cut BMW's cabling, BMW can't complain about anything.
Check out this link how I did my installation on my K1600GT https://www.innovv.com/forum/innovv-k5/and-another-installation-on-a-bmw-k1600gt-with-pictures
You are right to be careful about cutting into the wiring of a canbus-equipped motorcycle, as you can do expensive damage. But as there is not yet a Hex ezCAN / Denali CANsmart accessory manager for this bike, that is what you must do to connect the yellow switched power wire.
All BMWs have an AUX power outlet (DIN / Hella), you can tap into the positive wire for it. Also, you will find a spare connector up front somewhere for GPS installation that you can use. You get a male connector with pigtails at your BMW or Garmin dealer.