Don't get that cupholder statement. It's right there next to gear lever.Just went for a drive in a BMW 3-Series today and noted about 10 annoying things in the design: Ridiculous cup holders in the dash that the driver can't reach, overly large rearview mirror blocking forward visibility, not enough tinting in the windows, fan speed that goes from nothing to a hurricane in one setting, mushy brakes, overly complex iDrive infotainment system, gear selector that you push forward to go backwards, creep that is way to fast, and... yes, uncomfortable rear seats where anyone over 5'9" hits their head on the ceiling.
There is nothing to see if rear view mirror would be smaller. There is the camera/rainsensor stuff and also black dots for shading. Though I like Tesla's edgeless design more.
Tinting can be factory equipment but also aftermarket.
Fans speed has 7 manual settings and 5 autosettings. Did you use AUTO fanspeed adjustment? This setting depends on how far off is actual cabin temperature.
Mushy brakes? What? You mean soft when pushing slowly? BMW has lots of brake assist functions. For example if you press brake faster than usual though not hard, it will brake with a jerk. If you push slowly it will smooth out the deceleration event.
iDrive has been the crown of infotainment systems for 8 years. Pretty much all independent car reviews state that. I've not seen better solutions that do no require touching a screen.
Gear selector should always be that way - forward for reverse and backwards for forward. Visa versa is not safe, long story.
Creep is not sluggish, true, not sure it's bad.
5'9" might be too much for smaller sedan, though there is touring for those occasions. Maybe not in US.