Not really an on board computer…. No single DIN GPS units were available when I needed to fill the hole in my 1970 S2’s dash. I used an early jailbroken iPod for years but decided to dump the bluetooth GPS it required and update it with an iOS15 phone. I had an iPhone SE that wasn’t being used so I loaded it with maps, speedometer, clock, g-force sensors and music apps. The housing is 3D printed and it fits and works well.