Arrests seem like overkill. Ask them to stop, issue a fine, whatever. Sure I get you're asking for any enforcement at all. But hyperbole has a polarizing effect on discourse we should try to avoid, IMHO.

Yes, I agree, but really we shouldn't even be comparing "arrests" and "fine". The latter is a punishment, and the former is a practical measure to prevent a future crime (such as destruction of evidence) or to prevent someone from evading justice (by destroying evidence, hiding or leaving the country, for example). Obviously some police forces do use arrests and searches and confiscation of "evidence" as a form of extrajudicial punishment but that shouldn't be allowed.

Arrest? No, but if you've done illegal modifications to your ride then being forced to get it from the impound lot seems fairer to me compared to a ticket you can pay at your convenience.