To follow on from this post, I have found that my headunit has a 1280x480 resolution display.
I had an update available on the Autokit app the other day which has fixed the issue with the "Image Scale" options. If I select "Original", then it displays more how I would expect it to... but it has large black borders to the left and right... so a decent chunk of the screen is unusable. If I select "Fullscreen", then it just stretches it wide.
While its not terrible, it's obviously a stretched image. I've added two photos to show the difference. Apologies they're from a slight distance, I couldn't get my phone any closer without unplugging it.
I have found this thread on the official Android Auto forums that suggest 1280x480 is definitely possible, it just needs the manufacturer to implement it... so if I'm understanding it correctly, this means the AutoKit app needs to support that resolution. https://support.google.com/androidauto/thread/8844203?hl=en
I have also discovered how to enable the developer options in Android Auto. The screen resolution options here do not make a difference. Well, always use 480p makes it worse... but allow up to 720p, 1080p or allow negotiation does not make a difference.
Does AutoKit support this resolution? If yes, how can I select it or is there a specific version I need to install? If no, how can I request it?
I am currently running AutoKit version 2021.01.08.1651 and box firmware version 2020.10.27.1239.
It seems this is a relatively common resolution as I've found detail of various units that run this... so it seems reasonable for the app to include this support.
I've had the same issue since day one. I tried their customer support several months back and they acted like they had no idea what I was talking about. Eventually they just stopped replying. The HUR app has no trouble adjusting to the 10.25" so I've been using that, but I would really rather use the dongle. I have no idea why this is so hard to get right. I hope an update fixes it eventually.