How do I go about fixing or bypassing this screen

My setup:

8100NEX

Nexus 6

I updated my phone to a new rom and now this happens... I dont understand how a rom on my phone can cause this.... anyone have insight?

for sure a ROM can lead to this . android auto makes the phone act on your headunit screen . so if you have a glitch on the ROM it will be reflected in your headunit . By the way this is the 1st time to see a message like that !

No, thats not the first time that message appeared.  Anytime you plug a phone into the headunit for the first time, it pops up on the screen asking "Do not display this notice again" with a check box and an accept button.

The reason the screen looks screwy like that is because the custom ROM you are using is not using the native DPI for display.  Granted, your screen is not mirrored, but this exact incident has come up before and solved to be the custom DPI on ROMs.  

FYI, stock DPI for a Nexus 6 is 560.