Complex sentence: In 1993 the car was used on a part-time basis by Dominic Dobson, proving uncompetetive, the car was retired never to be raced in CART competition again.
Split into simpler sentences: In 1993 the car was used on a part-time basis by Dominic Dobson. Proving uncompetetive, the car was retired never to be raced in CART competition again.