Don Johnson raced a No. 15 1957 Chevy convertible to four straight championships from 1969-72 at Saugus Speedway. His son ran the No. 15 at Saugus and Toyota Speedway at Irwindale. His grandson, who races in the NASCAR Super Trucks division at Irwindale. got to run the family 15 for the first time two weeks ago. He won in his debut with the 15, his first win of the season. FInd out how the Johnsons were able to get the No. 15 back in the family fold in The Signal.