I have so much room under the back seat I was thinking of TWO 2000w 18" subwoofers (that would probably double the weight of the car). I don't use iPhones but the entertainment center is in the passenger seat when I push the throttle down.
You are correct about the rest of the stuff, A/C vents, power roof and all that. They are all together, but at the parts warehouse and not in the car!
I thought about carrying a battery powered tire pump as there is no room for the front or rear tires in the trunk. A plug kit and pump would take care of most issues. I can fit a space saver in the trunk and put the actual wheel in the passenger seat if I were alone.