Given that all the parts exist, I am wondering why no electronics manufacturer seems to have coupled a GPS receiver to a pico projector to make an aftermarket version of a Head Up Display GPS for car dashboards?

Some cars makers (eg BMW) have built-in GPS HUDs in their top models. Given the relative hassle of mounting a GPS unit or a GPS-enabled phone in a car, I would have thought that a small projector that sits on top of the instrument binnacle and shines up onto the windscreen would be a sell-out.

Perhaps these exist and I have never heard of them or maybe no-one’s thought of it and I have just blown a patentable idea.