Im using wai's mp4/17d at the moment. I like the detail on erwin+guyons one but running the crappy graphics that i am at the moment, wai's is better for the overall shape.
For the jaguar, im using fusions coz i just want a 2003 car rather than a 2002 model. I dont think its bad, and i cant wait for erwin/guyons, its looking good atm, but its got a really really dodgy damage model.