Well, I meant "friend" in the loosest definition of the term. No intent to offend.
As for the others, too bad. I have not seen this in my region. In fact, just the opposite. People arguing that they ought to be in a tougher class (where they will get their butts kicked) and the event guys saying "don't worry about it."
It may be that your local organizers allow some leeway. If so, so be it. I'd rather be up front about it.
If you just want to have fun and mod your car, you can always see if there's an "open" class for all the catchalls. Otherwise, remember that this is a test of your skill as a driver. There's no money in it, at least not locally. If you "cheat," who are you cheating?