A3 steering wheel controls/ BT module

[RobP99]

Hi I'm new here, and after having I BMWs for many years I'm very happy to say I'm well impressed with my A3 even though its 14 years old.  Three things I would love to know are:

1. Can you change the locking so all doors unlock together with coding, I've looked though the settings and cant find anthing in them
2. Can I add a BT module to the SatNav radio, it has phone options but it say on the screen that its not installed.  I dont want to change the head unit for a new one because it has the factor Sub fitted. 
3. Can you change the steering wheel to one with controls, I've seen them on the same year car, so I assume these were optional extras when it was ordered from Audi. 

Thanks in advance for your comments. 

[cliffcoggin]

Rob.

In regard to question 1, the first press of the key fob button unlocks the driver's door only, a second press within five seconds of the first unlocks all the other doors.