Yup, been there, done that, on my '98 E-class.

It's an easy process, but some assembly is required The entire head unit/door assembly slides right out of the dash. But to release it, you have to remove the ashtray.

Start by removing the shifter surround - the wood piece with the window switches etc. in it. It just pulls up - a good deal of force is required. Open the cupholder door to get a good grip on the tail end. It need not be completely removed, just pull it up and set a bit aside.

At the very front of the area covered by the surround are two phillips head screws. These retain the ashtray frame. Remove them. Open the ashtray door, remove the ashtray, and pull out the ashtray frame. Move the gear shift lever out of park to ease this step. The ashtray assembly has an electrical connection you'll have to remove.

Now for the head unit. Reach into the opening where the ashtray formerly resided. At the back of the head unit/door assembly there's a big plastic tab. I forget whether it's at the top or bottom. Pull it to release the catch which retains the assembly in the dash, and slide the assembly out. You'll have to unplug the head unit as well - mine just used an RJ45 (i.e. phone cord) style connector, yours may differ. You can now take the entire head unit/door assembly somewhere safe to work. The head unit removes out the back of the frame, not the front. There are several plastic tabs which retain it in place.

I also removed the handsfree microphone, the handset, and the transmit/receive unit from the trunk. Anyone wanna buy a phone cheap?

I've not gotten around to ordering the plastic insert to convert it to a storage tray. If you do so, would you please post the part number - my parts guy struggles with requests such as this one.