Years ago when I was in the tire business there was an unwritten rule that you didn't have to deal with more than one of the following groups because they were so obnoxious (that's stating things much more politely than the way it was usually stated)
1) BMW car owners
2) Cadillac owners
3) Corvette owners.

I owned a pair of BMW motorcycles over the years, and people used to get embarrassed when they remembered that after complaining about BMW auto owners. I'd just smile and tell them I understood.