I told my dad I would put my sony double din in his 2011 SL550 and I cannot for the life of me find a guide or any information on the last years of the R230. Every guide or install I could find was for the earlier r230's before facelifts. If anyone has any information on what is needed for a complete sound system overhaul it would be greatly appreciated.

What I need:
Radio harness to keep the factory steering wheel controls with an aftermarket head unit
Trim bezel to install the radio in the dash
How many speakers/ their sizes (speaker bracket links if possible)
Info and wiring harness on the factory amp
How to take these out and swap them without breaking anything

If I can get enough info on how to do this I'll post a guide with pictures to help others, because not being able to figure this out has been infuriating.

ALSO if there's a model code to differentiate the 2009-2011 SL's from the rest of the r230's that would be great to know, but I can't find any info on this.

I have read many threads on this subject in this forum as well as others. I have a 2011 also and was looking to do the same. These systems are seriously over engineered with optical speaker wiring as well as being very, very tight. I opted to simply add on a Bluetooth dongle so I could play Spotify and Amazon Music in mine. Way too much hassle for the gain in my opinion. Much better mods are the Smart Top and removal of secondary cats.

I just posted a thread about this. Go to :
https://mbworld.org/forums/sl-class-...ml#post8278836