I purchased the new double din bracket or cage (Part number 2106890916 - Reinforcement for 2000 - 2003 E320 - $30 plus shipping) and new burl wood double din bezel or console (Part number 21068023367400 - COVERING - $243.80 plus shipping) from Parts.com. The new bezel or console had to be ordered from MB Germany, and it comes with seven (7) button holes across the top. Since my old burl wood console only had three buttons across the top (including the emergency flasher button), I had to order four hole fillers or covers for the four extra holes in the new burl wood console (Part number 2026831310 - BLIND COVER - $5.29 each), also from Parts.com - Joe was quite helpful with researching and handling the order. (See photo with blank buttons.) The most difficult part of the conversion was removing the old cage or single din reinforcement bracket. I simply read the threads on how to do the conversion and followed the step by step directions of those who came before me. I owe all of them a big thank you for the great information and directions. With that said, once you get to the actual single din bracket, be patient and persistent, it will come out. If I had it to do over again, I would probably remove my glove box, as suggested in some of the threads. This might make it somewhat easier to remove the single din cage and install the new double din one.
I purchased the antenna adapter and wiring harness from Crutchfield. (However, I didn't really need to use the wiring harness since my radio/head unit came with the Euro harness. It was plug and play.) Yes, I did the wiring myself. The most difficulut part was wiring the backup camera. I had to tap into my rear backup light wire. I also tapped into my rear lamp wire which is the same as tapping into the headlight wire in order to have the radio dim when I turn on my headlights at night. I took a chance and purchased the radio (7" DVD Navigation Radio) direct from China from chinavasion.com. I bought their Gladiator unit and it is virtually a perfect fit. It works great and the sound is very good. I am quite happy with it. (cost under $300) Check out the site and you decide. I used ABS plastic to hide a 1/8" gap between the radio and the double din opening at the top and bottom. I bought the abs plastic from parts-express.com. As I said in my original post, check with parts.com for the double din burlwood bezel and cage/bracket. Better price and faster service than Netherlands guy.
My car is a 97 E320 that came with the factory radio unit. The amp was built into the radio. No external amp unless you have the Bose system. If so, I believe there are post that guide you through how to do the wiring.
A few more things that might be helpful to those of you doing the conversion, the wiring harness I purchased is the same one used for a VW. If you purchase it from Crutchfield, as I did, it will come with instructions. Just enter you vehicle make and model and search the Crutchfield site for radio wiring harness. One of the modifications you may need to make is to cut the body of your factory radio harness in half (separate the A and B connectors) in order to get the ISO harness (adaptor harness) to plug into the factory harness. Don't be alarmed, I did it and it was big deal. Just wanted you to know. Crutchfield explains this in their instructions. If the aftermarket radio you install requires you to tap into your car's speed sensor wire, I read somewhere that the 97 e320 has a speed sensor wire built into the factory wiring harness (I believe it is connector A, pin 1). This is what causes your radio to increase or decrease the volume automatically when you drive fast or slow to compensate for road noise. (My old Becker unit did this, which was actually an interesting feature.) Anyway, look at your factory harness and you will be able to identify the A and B connectors and the pin numbers for each wire. Lastly, the backup wire (hot or +) for my car is the gray with yellow strip wire and the rear lamp wire (hot or +) is the gray with black strip wire. Have someone put the car in reverse while pressing the brake pedal while you test for the backup hot wire using a 12 volt tester if necessary. Turn on your headlights and test for the rear lamp hot wire if necessary . I hope this all makes sense. It really is not as complicated as I am making it sound. Just trying to be helpful as so many others were for me.