My friend's g35 is having a problem where his driver side black rubber door button stopped working.. Any ideas?

 

I didn't know we have rubber buttons?

 

it looks like this..

 

Only Intelligent Key cars have them. It's the button you press to unlock the door.

Is your friend's car under warranty still? If so, take it in

 

check the battery in the remote. My rubber button did not work when i got my car, but the key less remote would start the car. I guess it has some sort of reserve to allow the car to start with the battery low, but not unlock the car. I think the key icon will flash after the car is started to let you know its about dead. Got new batteries and all was fixed.