Complex sentence: Frank Halford raced his car twice in 1925 and 12 times during 1926, then he sold it to Captain G. E. T. Eyston, who would later hold the Land Speed Record, to race during the 1927 season.
Split into simpler sentences: Frank Halford raced his car twice in 1925 and 12 times during 1926. Halford then sold the car to Captain G. E. T. Eyston, who would later hold the Land Speed Record, to race during the 1927 season.