They will not hesitate to change the Electronic Control module and maybe the BSI also, just to be sure that your car don't fails in the worse moment and kills you. This could start at 1500 euro or much more depending on the brand. They will not understand your "right" to run Doom in your car.
Think also that currently some secondary car systems in many brands can be deactivated online, without creating a situation of danger for you, but making your driving experience really miserable if they want.