Read the thousands of posts of people having issues over on the google forums. Mine has not worked right since May 2017. Heres a short list of what it does:
Connect phone via USB, starts android auto. Locks up. Must unplug the phone and once had to shut the truck off and restart it to get the radio and anything else back.
Start navigation. Seemingly works fine till your down the road 10 minutes then vehicle screen turns completely black, then the bottom AA icons appear, then white blank navigation screen, then loads roads and names, then locates you again in 2D view, then resumes your route in 3D like nothing happened. It then does this every 2-5 minutes of black screen restarts.
When attempting to send a text it goes like this:
Me: OK google
AA: (ba-ding noise) What would you like me to help you with
Me: Text john doe
AA: OK what do you want to say?
me: (ex

What time do you get of work today?
AA: ok i got "want to say what time do you get off work today?" - do you want to send it or change it (ba-dink noise)
me: send it
AA: Im sorry i didnt understand that do you want to send it or change it (endless loop)
That happens every damn text - notice it added itself to the beginning of my text like its listening too soon. I can get it to send if i start saying "send it send it send it" while its talking after my text because its listening for my response too soon and hears itself talking.