We bought this 1998 Mercedes-Benz E320 on eBay!  Yes, eBay!  I've saved the auction page for posterity.  Click back on your browser to come back.  And this one as well.

This picture should make it apparent that I use Zaino Brothers car care products.
 

I decided to add some goodies to this car.  What you see here is the finished product.  I added a SmartEQ hands-free kit for the cellular phone, A Hirschmann cellular/GPS antenna, an Escort Passport SR1 radar detector, XM Satellite Radio accessed through this Pioneer GEX-FM903XM adapter and two DC power sockets.  The Mercedes cigarette lighter does not work well as an accessory plug, so these two plugs give me reliable power.

All of the components in the center console can be hidden behind a paneled door, which is a standard manufacturer's part, leaving the car's interior looking unaltered.  In fact, the panel used to hide the Mercedes Analog Phone, which was worthless even when the car was new.

Here's a closer picture of just the panel area.  Top left is the SR-1 radar detector, bottom left is the Pioneer control unit.  The power ports are on the right.

The XM control box is mounted on the bottom side of the rear deck in the trunk. 

Unfortunately, there are a few changes outside the car.  First off, the XM radio requires an external antenna.  This Pioneer antenna is bolted to the trunk lid and stands about four inches tall.  It is currently the least obtrusive of the four antenna options.  I hope they will provide a less noticeable antenna in the future -- maybe this diameter is okay, but it needs to be more flush with the car's surface. 

One of the alternative antennas mounts on the roof using adhesive and has an eight inch wire that runs from the antenna's location to the rear window, where it is snaked into the trunk of the car underneath the window's molding.  Ingenious design, but very ugly.

The trunk mount doesn't bother me so much, but Leesa says it's ugly.  This car doesn't have any other external antenna.  The radio and analog cellular antennas are located in the bumper.

The radar detector also required some modifications.  First, in the back, a rear laser detector needed to be placed either on the license plate, or underneath the bumper.  You can see it beneath the bumper here. 
 

But the modifications in the front are more dramatic.  There is no room behind the top or bottom grille for the front radar & laser detector.  The bottom grille, however is goes have a good amount of room to work and I eventually concluded that sawing into the plastic grille would allow a good placement.

From this view, the detector is barely visible.  It is flush with the grille and from normal driving distances, it shows up only as a patch that's a slightly different color.

This picture, though is from a very low angle and is brightly lit & this shows the installation clearly.