After I have done the rear and front facelift, i wondered if the interior could be done. After researching for days I could not find a specific answer to this. I was checklng with a local car electronics shop n my country which does electrical jobs on most cars and which is very good at this job. This week I called them whether if anyone whad achieved this and they told me that they ad retrofitted PCM 3 to a 06 Boxster and everything worked flawless with changing the bose amplifier with 997.2 one and some wiring modifications. But he said that the PCM to be purchased should be with some certain part number according to the VIN. I will talk and learn further on this soon.
I wanted to let the ones know that it is possible to do this since I know many people want to do this.

 

It believe it's possible, but very costly! My understanding is that most of the cables need to be updated along with the unit, and then you need the dealership to work on the programming of the unit. I don't know if it's worth the hassle, but each to their own. If you have it done please post pics. Good Luck!