That’s sad to hear. While I partly understand you I must say the hardware issues you have are up to you. I chose the other route and bought a used 2 year old flagship Sony xperia 1 with wireless charging, headphone jack, excellent camera, expendable storage up to 1 TB, 4k OLED display, DP alt mode and what not. They are fairly cheap since the one I got is stuck on android 13 and therefore not too desirable. With /e/ you can upgrade to higher android versions and so I got the opposite experience from you. Flag ship phone with everything I could desire for an absolute steal. Yes you do have to put up with potentially damaged used devices but in my experience it is still cheaper at the end of the day.
Regarding android auto, there are ways to get it running
Although I must say it only worked iffy for me.
If you do expect the absolute state of the art experience you do need to go to first party android or iOS and there will most likely never be another way. With data privacy awareness it is always a balancing act between convenience and data protection/control of your property. If it’s actually not as important to you who gets your data, you don’t want to put in any effort into setting up your phone and you don’t mind switching your phone more often (or trust them to stick to their latest 7 years update policy) then I would even recommand “stock” android from google, because you will always get the latest updates and features.
If you prefer data privacy, virtually unlimited software updates, open source software and don’t mind to put some effort into your most powerful everyday tool only then I would actually recommend staying on /e/.
It has always been a choice between convenience and data privacy and always will be.