Is there a way I can turn on the parking proximity sensor? Is seems to have been disabled by the previous owner.
Also, why is it that the wing mirror only sometimes adjusts itself when parking?

Before I hear any smartass comments about my parallel parking abilities, we park on the street in some very tight spots in Brooklyn.

 

Not sure about how to reconnect parktronic feature (suggest you do a search on "disconnect parktronic"), but I can answer your second question...

The passenger mirror will only swing down when in reverse if the **** used to adjust the mirrors is pointed at the right mirror.

 

Check for a button with a p and some lines that look like sound waves. If that button doesnt work theres probably a problem with the system.