It's like with the R142s, the propulsion is the same for all the cars but they all sound different if you know what I mean. The sounds were actually that low in 1101 but for those that want to hear the propulsion, use 6981! And you can swap the loop.wav sounds around for a loud, medium or low HVAC. I really want to get a third version of the R142 though, using Bstyles sounds.