From what I understand, the car is better off in gear than neutral when coasting. When in neutral, the engine has to keep fuel injection going to prevent stalling, but if the car is in gear coasting, the wheels and the drivetrain keep the pistons moving, and supposedly the car is smart enough to not bother with fuel ignition.
I dunno if it's correct, but it sounded plausible. Besides, it's better to have control over your car for that 1 in a million time you need it.
335xi sedan 6MT, Premium, Cold Weather, iDrive, CA, iPod
Black Sapphire Metallic, Black Leather, Aluminum Trim
European Delivery: April 28 - May 7, 2008
Performance Center Redelivery: July 11, 2008