does anyone know if it's possible to get steering wheel audio controls dealer installed? if not could a custom audio shop achieve this setup with either a stock head unit/audio system or with an aftermarket one? anyone done this or know if it's possible??

 

You can definitely get it done with an aftermarket one. For the Kenwood Nav (and other Kenwood head units) I'm looking at, there's a $30 piece that mounts on the wheel.

Also - you might want to post this in the Lexus Electronics section of CL, you will likely get better responses.