Complex sentence: Don worked as a used-car salesman at the time Anna Draper found him, and on at least one occasion enjoyed the company of motorcyclists and hot rod enthusiasts while he was visiting Anna in Southern California.
Split into simpler sentences: Don worked as a used-car salesman at the time Anna Draper found him. Don enjoyed, on at least one occasion, the company of motorcyclists and hot rod enthusiasts while he was visiting Anna in Southern California.