This may not help you but i can see 3 reasons not to put a 12a in a 800kg car 1st theyre heavy, 2nd they don't put out much power, 3 cops hate rotories so even when theyre legal they just book you for something else, think out of the square, 2.2l and light, 2L suzuki vitara with a gti head or V6 vitara these come in 2L 2.5L 2.7L and 3L all these motors are very compact, light weight alloy and boxs are easy, i think a ke10 with quad cam 24valve 6cyl would be cool