Complex sentence: After the 1993 seasons of both the WSC and JSPC were cancelled, and with the RX-792P shutting down after the 1992 IMSA season, Mazda found itself out of sportscar racing altogether.
Split into simpler sentences: After the 1993 seasons of both the WSC and JSPC were cancelled. And with the RX-792P shutting down after the 1992 IMSA season, Mazda found itself out of sportscar racing altogether.