For a number of years I used GPS and an old laptop here in the USA. Interesting, but very dangerous I think. Laptops are too large for most/my car(s) and distracting to operate. I'm not a monster-car or SUV person.
For motorway driving, I stopped taking the laptop and just preprogrammed route-change points into the GPS as waypoints. Not suitable for other routing purposes.
The GPS was included when I sold my sailboat. I'm still thinking of a replacement, but using a laptop for in-car navigation isn't part of the picture.