I have done a couple of searchs and I have gotten a lot of good info, so I'm going to post my thougts to see if you guys think it will work.

This is for my 123 wagon, the head unit has finally died, and it has stock speakers.

I'm thinking about the Sony CDXF5505X radio head unit. What we like is it plays mp3s and is xm radio ready. Oh and it is cheap 189.00 at cruchfield which claims it will fit my car.

For speakers I was thinking about Sony XS-W4021, cruchfield claims they will fit and are 4" speakers, I thinking about using them for the front and the back.

Additionally I was thinking about adding some small sub in the hatch of the wagon. I think the I can fit and 8" in this is the on I was thinking about Rockford Fosgate P18S4, but I will need a small amp to drive it. which will not be a big deal.

any thoughts?

The front speakers are only 3" speakers I believe. Watch out for Crutchfield. They tend to either say they have no speakers for the 123 or they will sell you what they think will fit, which theu don't and you wind upo returning them.
The front speakers should not have tweeters that protrude above the top of the speaker or the covers won't fit back on.
I mounted an aluminum plate just in front of the spare tire cover area, attached to it is my 12-CD Pioneer player, driven from a Pioneer head unit of course. The DEH-series Pioneer radios are quite nice with XM satellite and some MP3 units available now. Installing the radio is not too difficult.

I use a A/D/S/ power plate under the wood floor in the rear (the removable floor that comes with the NON-third seat version car. If you have the third seat I don't believe its recommendable that you use a power amplifier under there because the wires would get caught up in the process of lowering or raising that third seat. Look for a old A/D/S/ unit they are very reliable for this application. Forget those huge amps on the market now, you don't need a LOT of power, unless you have a tote box size subwoofer, and it should use a separate amp anyhow. You can mount the amp for the sub woofer on the sub box itself.

As for speakers, I have a set of small monitors made for use in a home, mounted in the back of the wagon. They are wood, not plastic. Search for bookshelf speakers or mini monitors on eBay there are many that would work well in the back of your wagon and actually sound quite excellent as long as you have 20 or 30 Watts to drive them.

There is no way the rear speakers in the 300TD will ever sound good.
PM me for more details, someday I will take pictures of the setup.

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

Dieseldiehard,

what do you think about the Pioneer DEH-P4600MP, seems like a good inexpensive one.

Most importantly it has xm radio. Do you think it will work with a sony 6 disk changer? I have an older one I never installed in a car laying around.

If I remember correctly it has a large blue plug.

I like the Pioneer. You should forget about the sony speakers. Go with infinity or jbl, they sound good.

I'm a pioneer fan myself.

Alpine has a radio that is not bad that has XM Tuner built in. that is also an option not sure if it does mp3.

The thing I like about the pioneer is that you can easily add aux input to it as well.

The 4600 is a pretty good radio. I have the 8500 in my car, I love it. Just pop in a disc with 150 songs and they play perfect.

Alon

__________________
'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

What size are the stock rear speakers in the 123 wagon?

__________________
'81 300TD turbo <<sold 12/05 to another diesel nut

About the same size as the fronts, butted up against the roof.