From the MSPU story:
Now in a final blow to those who were hoping to access their Windows Phone apps from their in-car console, it appears Microsoft has completely left the consortium, with its logo being removed from their website within the last 2 weeks.
Supporting the open standard for car connectivity was the last opportunity for Windows Phone users to actually get good support for their devices in their vehicle, as the market becomes increasingly saturated with the proprietary Android Auto and Apple Car Play standards.
Microsoft’s new play for a presence in the car market is their Connected Car Platform, but this involves Microsoft mainly providing the back-end and a selection of their services to car makers, and offer very little for day to day Windows Phone users.
Which is slightly sad to see, but not a huge surprise. Just another Nokia-started initiative which lost momentum under Microsoft's reign? Mind you, away from the top end of the car market, surely most people just use integrated Bluetooth functions in their cars? So voice call handling, contact dialling, navigation, music control, all of which can happen very slickly without needing Mirrorlink, Apple Car Play or Android Auto?
See also my mini-tutorial on working (nearly) hands-free with a Windows Phone or Windows 10 Mobile handset when at the wheel.