And before the Cosmo there were some navigation systems using a gyroscope (they were not GPS based) like what Honda did in 1981 for the Accord : https://en.wikipedia.org/wiki/Electro_Gyrocator I would be really curious to see what such a system gives in practice.
Since there are indicator sounds that are programmed so you only hear it inside the car, can that perhaps mean a speed chime can be possible? Or is it hard to implement on a different matter?
Please tell me you're not Ivan Lochcov by any chance? Judging by your name, you seem awfully suspicious, because Ivan pulled off that same tactic before. Aaaanyway, can't wait for the release