I just learned something new, so I thought I'd share it with you all.
I have the 2008 Passion, and it has the automatic door locks: when you start rolling forward (above 10 mph) the doors automatically lock. At least they did until I had the 2.0 software update/battery replacement. When Mercedes replaced the battery, the auto door locks stopped.
Eventually, I consulted the owner's manual: and found out that the auto locks can be turned on and off...cool!
When the car is off, pushing the "lock" button on the dash, while simultaneously holding down the "lock" button on the key fob turns autolocks on...there's a "beep" ...
holding down the "unlock" buttons turns autolock off...