That's not a realistic option - most cars use their head units to control everything, from audio to car and safety settings. Those are essential features you'd be missing.
I've had this problem a long time ago (10 years) with my Honda and was able to pull out the control module out of the dash and just leave it in the space behind the new dash. But that's a case by case solution.
Honestly, the blame lies with the carmakers. They made these terrible digital dashboards in many cases with no after market upgrade paths. Obviously their incentive is sell/lease you a new car every few years... so why would they make it easy to upgrade. No incentive
Biggest reason I ended up getting the 2016 model vs 2015 (which had a much bigger discount) because of Carplay/Android auto. I won't be a frustrated by the digital NAV that never is upgraded.
I'm hoping the Carplay/Android auto compatibility is there for at least 6+ years of new phone models. But honestly I don't know how much I trust the above mentioned phone vendors.
