Ahem... XRT/XRR looks like RX7, and RX7`s DOES backfire even if it was stock, especially FC RX7.
And don`t start arguing what car it looks like, use your imagination and add the sound files you like most on the cars. RX7 was just an example of a stock car which backfires.
And even if it wasn`t XRT/XRR, all the others are racing cars. So they are modified anyways.
srry 4 double post but it wont work maybe i messed up?
edit never mind i figured it out and this is so good it kinda sucks its not really worth it u need it to b louder and better sound