n00b questions 2019+ RDX

Hi Friends,

Time for a new car. I used to have a TL 2008 which was pretty much built like a tank.
Then I bought a Tesla Model S, nice car but a fragile egg, crappy interiors with very high repair costs.
Since I've had good experience with Hondas & Acuras, I'm giving the RDX a pretty serious look.
I have a few questions.

1. Lately manufacturers have opted to build body panels using aluminium, reduces weight but repair costs are astronomical. What are RDX panels made of?
2. How bad really is the infotainment system? Coming from a Tesla, I will greatly miss Autopilot, and having a buggy infotainment system will probably frustrate me to no end. For instance, how reliable is carplay? How laggy is the system? How buggy is it? How often do you need to reboot it?
3. Any differences between 2019 and 2020?
4. How annoying is the auto-start on-off thing? Coming from electric driving, I'm no race car driver, but did appreciate the acceleration and instant torque of electric. How bad is this idle stop thing, compared to say a regular ICE?

Thank you!