I just got off the phone with CFPB - unofficial guidance only but I wanted to relay and clarify a bit from the original post:
First, the 'average rate' is to be determined by each bank by looking at their current market rates for the area(s) they operate.
Second, from the webinar handouts (I wasn't able to participate live, I only reviewed the materials courtesy of a co-worker last month) I was under the impression that we needed to compare personal property loans (commonly mobile homes) with this 'average rate' instead of the standard APOR threshold comparison under the APR test. That is INCORRECT!! The average rate is needed to determine if you have bona fide discount points for your points and fees test.
My apologies for any confusion this may have caused.