I don't know if this is in the owner's manual or not, but I just found it out this morning... If you hold down one of the paddle's it will automatically put the car back into drive (if the shifter isn't in manual mode of course). So if you just want to down shift quickly for a pass and have it go back to drive, you can do that. I think you have to hold it down for about a second or so before it will switch back to D.
You can also do this to force it back into drive whenever you want. Say you down shifted, and then go back up to 7th, you can then hold it down so that it goes back into drive mode.
It's uses are probably pretty limited, but nonetheless I found it pretty cool.
