iDrive
A feature developed by BMW to make things more simplistic. It takes away all the unnecessary buttons and puts it all into the iDrive. A nob in the middle next to the driver that moves forward, back, diagnal (in 7-series), left and right, and down. The iDrive is incredibly easy to use if you give yourself 5 minutes to try it out. There is a Menu button besides it if you ever make a mistake or dont know what menu you have gone into. 

There has been many criticisms made to the iDrive feature about its use and about its complexity. However, this has only been the case of the 2003-2004 7 series where it was quite confusing; however it has since been fixed. Mercedes and many other companies have been known to copy it...even though they complained about it in the first place.

The iDrive can also come with voice activation which works with any voice (you do not need to program your own words into the system...) and this helps the driver go to a specific place or navigation, or even change the cd instead of having to go through iDrive.
Dude1: Check out my new BMW 5-Series...iDrive is mad
Dude2: It's a bit confusing...

Few years later

Dude2: Check out my new Merc S-Class...check out its new nob in the center. Controls everything. Easy to use
Dude1: Thats exactly the same as my iDrive...Works exactly the same...Only thing is, my iDrive came out 2 years before yours...