Bobo,
If you don't have the hardware, you are looking at spending a minimum of $500.00 to $800.00 assuming you can get used parts on ebay. If you go for new parts, you are looking at $1600.00 at least.
This is what the install kit consists of:
1 Base bracket A211 545 54 40
1 Processor bracket A211 545 63 40
1 Navigation processor A220 820 60 85
1 MOST fiber adaptor A211 540 68 33
1 GPS antenna splitter A210 820 24 89
1 Screw N 910 105 006 023
1 Nut N 910 112 006 003
1 Left rear trunk panel A 211 690 01 53 9C53
note: truck panel comes in different variations, you will need to specify the following when ordering:
1. If the car has fold down seat
2. If there is a cigarette lighter power outlet in the trunk
3. Color of the trunk interior (black or gray)
Follow this link:
OEM Navigation Retrofit w/ pics - MBWorld.org Forums
Good luck!