This struck a nerve...we had Engineered Racing Services, Karbelt Speed and Custom had a bunch of locations, so did Performance Improvements, Lucky's Performance, Straight Line Racing, Beatty and Woods (who campaigned an original SS/AA Cuda back in the day) and many others.
I worked for a year as a wholesale rep for Karbelt who was a Warehouse Distributor as well, calling on independent speed shops across Ontario. Not a bad way to spend your work week...

Besides mail order ruining the business, it needs to be considered that as the cars started to appreciate in value many dollars that would have been spent on speed parts went to resto suppliers like Year One, Legendary etc. Too bad...