Strange Problem
 

I have 2007 / 2.3l Saab 9-5 Automatic. When I switch to M (manual) and press the "-/+" shift won't change. When I press "-" it will volume down the radio. When I press "+" it will shift down. When I press the volume down key on the steering wheel it will switch to "aux".

Looks like all my buttons are messed up on the steering wheel. Do you have any idea /solutions?

It could be a bad clock spring cable in the steering wheel or something else faulty/misconfigured. Take it to a dealer and this is something they should address for free.