I have a 2005 C230 (Kompressor Sport) which, I am told by my local MB dealer, has the phone dash buttons, etc., because all models had the same dash trim with the option to upgrade.

My brother-in-law's E class has this system working and I like it a lot, but not for the $1,800 they want to fit the system I need behind the dash!

So, my question is, what is the cheapest, preferably Do-It-Yourself, method of fitting something, so I can use my car's audio, etc. for a hands-free phone.

I don't mind buying MB/OEM parts from the MB dealer either, if I can be told what I would need - I just don't want to pay for something I can fit myself, as I am quite capable.

I have an android smartphone with bluetooth, which I presume will be the method of connection, if this is relevant.

Thanks for everyone's help in advance.