Entered his first Indianapolis 500 in 1934, finishing 9th. Continued racing at Indy and came in 2nd in 1940 and 1941. Never won at Indianapolis, but did win a pair of AAA National Championships. Was challenging for the lead when Duke Dinsmore crashed directly in front of him and was thrown onto the track. Rex intentionally crashed into the wall to avoid Dinsmore. 1949, a dispute over prize money delayed the start of the championship 100 mile race for more than an hour, preventing what might have developed into a major when without a word, he got into his car and started circling the track. One by one the other drivers followed. He died during a race in 1949.