 Complete the following phrase:  There were two drivers present who did not take part in that years championship: Brian Henton, who drove a Theodore, and Héctor Rebaque, who drove a Brabham. The Spirit team also made its F1 debut at the event with Swedish driver Stefan Johansson and Hondas first turbo-charged F1 engine, which BBC commentator Murray Walker claimed had completed thousands of miles of trouble free testing. Tyrrell fronted with only one driver. Michele Alboreto was scheduled to race, but it clashed with his drive for Lancia in the opening round of the World Endurance Championship at Monza. Instead his rookie teammate, 32-year-old American Danny Sullivan, was given the opportunity to get more miles under race conditions having only completed in the previous two Grands Prix in 