Your wiring under the airbag looks identicle to mine.
From what I gather the wiring at the gear selector end is pretty similar on all steptronic BMW's from E46 on.
You can get to the gear selector wiring quite easily by pulling up the leather gaitor from the console trim. I did this by grabbing the bit between the ashtray and the gear lever - did not require too much force.
To get the wires from the steering column to the gear selector however you have to remove the centre console trim. There is a DIY guide here;
http://www.e90post.com/forums/showthread.php?t=137527
I had to get a wide bladed screwdriver with tape over it under the centre trim at the armrest end to get the first bit up as it is a very tight fit on my car.
It also shows removing the gear knob to remove the leather gaitor, but that should not be necessary for this job.