 The mid @-@ engine complicated the design of the four @-@ wheel drive system , and an innovative solution was needed to get drive from the rear of the engine to the front wheels . The chosen design took the front @-@ wheel drive from the central differential on the rear transaxle and sent it through the V in the centre of the engine using a quill drive , before joining an inverted differential . The clutch was a twin @-@ plate unit designed by AP Racing . 
