There's one thing about "newer" cars (mine's a 2014) that older cars don't tend to have, and that's the ability to make the car beep remotely. That is insanely valuable in large parking lots.
Bluetooth stereo: that, you could install after-market.
If you use Apple CarPlay or connect your iPhone to Bluetooth Apple Maps will remember where you parked your car once you disconnect. I use this feature quite a bit to know how far I have to walk back to the car when I’m out on a hike.
Though, I imagine an AirTag will give you more precise location.
Bluetooth stereo: that, you could install after-market.