Every time a penalty is given, LFS sends out an ISP_PEN packet. An InSim script can detect this packet, and send the command /p_clear [username] automatically with the ISP_MST packet. The penalty is removed immediately.
This solution requires an InSim program, as far as I know there is no way to remove all penalties without one, if you have a starting point.
Well.. you would need to create an Insim which removes the penalty immediately after hitting the object. I didnt understand him much quite either. But i reckon that he means creating an insim which follows given protocol. In this case penalty removing.
After having a closer look, it appears there is no way to remove autocross penalties at all. I wasn't able to remove them in-game as admin or with insim, so that's the end of that. I actually recall something like that being said once upon a time. If someone knows otherwise, don't be shy