 Complete the following phrase:  The JS19 was designed by Michel Beaujon under the technical direction of Jean-Pierre Jabouille, who had retired as a driver from Formula One the previous year. It was provided with a Matra MS81 V-12 badged as a Talbot. The chassis had side pods which enclosed the rear suspension linkage, which minimised disruption to the air flow, and had skirts running their full length for maximum ground-effect. However, when introduced for its first race, the 1982 Monaco Grand Prix, the team was forced by race officials to remove the portion of the skirts behind the rear-wheel centreline a subjective interpretation of the rules not clarified in written bulletins, which resulted in a loss of downforce that affected the cars performance. The team used the JS17B, with which it had started the first five races of the season, for the following races in the United States and Canada while the aerodynamics of the JS19 were reworked in wind tunnel testing. A single JS19 was present for the 