You're legally (and technically) prohibited from re-programming GPS modules, GSM modules, and probably many stuff in cars as well.
(Actually, maybe contractually when it comes to GPS modules.)
GPS et al would be non-functional if everybody could make a jammer.
(That’s not to say that app stores fall even remotely in that category.)
>GPS et al would be non-functional if everybody could make a jammer.
Then it should be illegal to make a GPS jammer. Making it illegal to reprogram a GPS receiver in any way is unnecessarily broad.
It would be difficult to catch in an inspection if you could reprogram the OEM parts.
I don't care about closed-course cars, though. Do whatever you want to your track/drag car, but cars on the highway should probably have stock software for functional parts.
This is silly. Prohibiting modifying car firmware because it would enable some methods of sabotage is like prohibiting making sledgehammers because someone might use one to bludgeon someone, when murder is already a crime to begin with.