In December 1984 Costanzo accepted an offer from that year's Australian Sports Car Champion Bap Romano to co-drive the Romano WE84 Cosworth in the 1984 Sandown 1000 as part of the 1984 World Endurance Championship, the first FIA World Championship event held in Australia.
The C100 was built by Ford Motor Company in 1981, and initially featured a 4-litre Cosworth DFL V8 engine, which was replaced by a 3.3-litre version of the same engine in 1983, after the car had passed to private hands.