The car uses an ignition cut on upshifts, which gives a rather loud bang on the upshifts from the fuel igniting in the exhaust. The crackle on the downshifts is also exactly as the cars sound in real life too. I guess it is linked to the player car sounds though.
2 good vids of the cars and the sounds they make.
Thanks for those vids, the cars sounds amazing. I saw them at the Renault world series event at Silverstone about 8 years ago and I don't remember them sounding that good.
Looks like I'll have to try and get used to it in RF2. Wish there was a bit more sample variation though