Android Auto?

[FlashGordon]

Why can't I open Android Auto or find it in my app drawer? 

[Sigma · Accepted solution]

There is a separate app for that now. The Android auto you're looking at will only work when plugged into a car headunit.

[SamsungUSABetaTeam]

If solution provided by @Sigma doesn’t help, please send us an error report with screenshots from One UI Beta App (Beta Feedback -> Send feedback-> Error Reports -> "Select Category" -> Input frequency and Description" -> Send (Top Right Icon). We appreciate your help for supporting beta program.

[detwetter]

This is the one you want:
https://play.google.com/store/apps/details?id=com.google.android.projection.gearhead.phonescreen