>>2645057norwegian here, you will not be recieved badly for being german, its just a few guys dumb enough to film their rigs going offroad in stupid places that caused some recent controversy. believe me we do way worse ourself just make shure you leave no trail, dont get caught and dont brag about it on social media.
things gets worse during winter since many of the cool forest and mountain roads isnt plowed, once they snow down they are no-go until spring comes.
you can easily avoid toll roads, i assume you dont come here to drive highways so just take the backroads instead.
however many forest roads are privately owned and maintained and they charge a toll to let you drive there, from 2 to 10€. if its just a box you put cash in or a sign to pay with an app you play dumb tourist and just drive, some have gates and card readers there you must pay so bring a working debit/credit card.
and do research, i see so many foreigners cramped into rest areas next to the road but if they just opened google maps in satelitte view they could see scenic campsites a few hundred meters down some forest road.