The built in variety are crippled in that respect because of liability issues. By providing those functions they risk us owners comparing the GPS speed, that is computed differently from the speedometer speed and complaining, regardless which is more accurate, and vis a vis the ADR, as well as being accused of supporting unsafe driving by flagging camera locations.
They have no liability for the portables.
The push back on some ‘fun’ commercials is evidence enough for me that is the case.
