click on the link and you will see it in action. its a Rig N Roll Sound Mod - Caterpillar Turbo Diesel. i havent tryed it yet but i will and let you know when i do.. you can also download the sound for it and put in Rig N Roll Game..
Download mod here --
http://www.megaupload.com/?d=RWOO5PKK
watch the video --