This isn't a bad idea. Beyond the concerns raised by other commenters, building a personal car from commodity components may not happen because we'll no longer

This isn't a bad idea. Beyond the concerns raised by other commenters, building a personal car from commodity components may not happen because we'll no longer own cars, but instead subscribe to a transportation service. The cost of which might depend heavily upon the cost and serviceability of the service provider's fleet. If your market doesn't mind riding around in automotive version of a no-name PC, the Lego approach might work very well.