IDK what the answer is, but I'm sick of seeing husbands, fathers, and just overall good men going to jail or losing their livelihoods for, at worst. modifying civilian vehicles the same way the federal government does in much larger volumes.
Specifically in the worst cases (which is usually the smallest percentage of charges) removing or disabling mechanical emissions devices (deleting DPFs/SCR/EGR systems), either due to failure, lack of parts, or preventing future expensive failures, FOR THE SAME REASON every diesel powered vehicle funded by our tax dollars removes or disables them. They get paid to do it, you go to jail.
This trickles down into did you sell larger tires? Were they tested? Did you sell an unregistered intake air filter? ILLEGAL!