Law is vague, intentionally probably. The way the law is written, it covers any engine, not just street cars. Lawn mowers, weed whackers, all of it. Police and government thugs are lined up against you.

Do the mufflers meet state inspection, noise laws? Have you done a db test at you property line with the engine running?

You could try putting effective mufflers on the car when ever it has to be run. Do they really need to be run at home? Very seldom I had to run my race car in the shop.

Or lawyer up. Or move. Sometimes you can't fight it without going broke or to jail.