Really? lose my house over a 2000 car.. I seriously doubt the government has time to do auch thing. Besides they make way more money on "tax cheats".. 
Its not the government you need to worry about. Its the pain in the ass lawyer of the people you sold the car to. When they run it out of oil or blow the head gasket and the next guy in tells them it can't be a rebuilt engine because it still has standard bore pistons in it. They see it as a windfall and call their lawyer.
That is why I never leave a trail when I sell a car. People have run cars that I sold them in a ditch and then complained because the suspension was bent and now they want their (my) money back. Or they call up 6 months later when the car won't start because they left the headlight on all night and somehow that is my fault. With a lot of people it just has to be somebody else's fault, no matter how badly the F up. Or they guy who was going to sue me if I did not take a car back because they ran down the previous owner and he told them the engine was bad. It was when I bought it, but it was fresh when I sold it a month later. He just wanted out of the deal because he bought the car for his grandson who just went off to jail. He spent hours driving around my neighborhood looking for my car. He showed up at 6:00 AM and waited behind my car until I went out to the car to go to work. Calling and overhaul a rebuild just gives that kind of JO the leverage to take you to court and win.