This.
I've driven many different types of imports as dailys, over a number of years now, and have NEVER been regency defected. I don't drive like a fkhead, and my cars are usually free of obvious visual mods, so that helps I guess.
If you're that worried than I'd suggest erring on the side of caution, and keeping it sleeper like. That or do as most do and just modify your car as you see fit, then when you get done just return it to stock, take it through regency then mod it back up again.