There are covers you can buy for your Cat. I used Dremel tool and engraved VIN on my cat. Also spray painted number with Heat Red Paint (Rustoleum). No self-respecting thief will risk stealing something he knows he can fence.
Those are good methods to change the appearance of the Cat you’ve got. If someone knew enough to ask for it, there are probably lots of privately owned Auto Repair Shops that would do this for a small fee. Bigger repair shops and dealerships might not think there is enough money in it for their mechanics.
“”No self-respecting thief will risk stealing something he knows he can fence.””
Do you think thieves have self respect? You mean, “can’t fence?”
Why don’t they just go in and steal the entire vehicles - take them to their chop-shops and paint them and drive them over the border?