Why quit posting ads over a few nuisance messages? Just ignore them and keep selling your parts to real Americans. Don't let them win.
If you don't like bogus texts just don't list your phone number. If you get a bogus generic email that does not specifically name your item, delete it.
Keep your parts listed on Racing Junk. I have over 130 sales on Racing Junk for parts I would still have if not for this site.