After graduating from Michigan State College, (now Michigan State University) Rockwell joined ROW Motor Sales in Grand Rapids, Michigan, as Service Manager in 1947. In 1951 he became President and General Manager. Rockwell has served as President of the Metropolitan Grand Rapids Dealers Association and the Michigan Automobile Dealers Association. Rockwell sold ROW Motor Sales in 1975 and joined Northwood Institute (now Northwood University) on the Midland Campus in 1976 as an instructor. In 1977, he was named Chairman of the Automotive Marketing Department and was appointed Dean of Automotive Studies in 1982 and full professor in 1987. Rockwell played a strategic role in the growth of Northwood’s Automotive Marketing curriculum into a baccalaureate-level degree program on three campuses with worldwide connections.