I was an area manager and embarassed how our group handled it.
Basically, if the MT didn't ask about it, we did nothing.
No mileage reimbursement, no pay for meetings.
When a smart MT asked about getting paid for mandatory meetings and/or mileage reimbursement on their personal car then we had to pay them both.

Instead of making this public knowledge to every MT we were told to just not draw attention to it and keep quiet unless someone asked.

Been out a while and not sure how it is handled now or was handled by other groups.