Anybody knows of a simple non-destructive anti-theft mode like a fuse-switch one can easily install himself on basically any modern car? I need something I can remove and the manufacturer/dealership cannot then see I used it (otherwise they may try to whine about me having broken the car manufacturer warranty).

One of my older (collectible) car has various anti-theft helpers, including trackers. I also remove its steering wheel (easy, no airbag). Then I disconnect the battery. But then my favorite on that car is a kill-switch I had installed on the fuel pump: it's hidden and you flip the switch, car stops instantly. That one if thieves want to steal it they either have to come with a steering wheel, find the trackers, find the switch, hook up the battery or come with a tow truck (they'd still need to get rid of the trackers though).

But yup I'd like to know if there's a simple fuse-switch DIY that's non destructive: basically something I can remove and put back the regular fuse and the car dealership would be none the wiser that I used one.

Anyone know of such a thing?