Mysterious "M"

The fender tag belongs to a ยด71 Challenger. Any ideas of what that "M" stands for?
(See: http://cgi.ebay.com/ebaymotors/ws/eBayI ... egory=6198 )
(See: http://cgi.ebay.com/ebaymotors/ws/eBayI ... egory=6198 )
Alaskan_TA wrote: so they must have had at least that many inspectors?