Not if you're already standing beside the car with the driver's door open, which is where I usually am when I decide I want to throw something in the back.
I have a habit of putting my handbag in the rear footwell behind the driver's seat if I'm carrying a front-seat passenger. I don't have to open any rear door to do that. I doubt if I'll be able to do it in a 5-door though.
Oh well.
Rolfe.