Hey, RSbob -- you didn't tick me off, that's for sure. I'm still running the Bose/Nav original head unit in my 04 CS so I can't comment (authoritatively, at least). But didn't want you to feel ignored.

 

Scroll back several pages and you'll find many threads on upgrading the head unit. No one has answered because it's something that comes up once a week and most of the regulars are worn out talking about it.

You don't have the base system. Bose uses the MOST fiber optic system and you'll need a converter to install a new system...I think they're around $100 currently. You will lose front to back fader control, but there's also a thread detailing how to get around that with additional amps (it's very involved). I also read there's a Russian built converter that allows fading but haven't heard of anyone installing one.
Steering wheel controls configure easily with most new systems. NAV will require a small antenna placement (I think many hide it under the center dash speaker grill). A small mic will also be needed for hands free phone.
Backup camera will require the camera and running the wiring.

 

Anything is possible. You could upgrade to a PCM unit but why go with the old. I replaced my PCM headunit with a Pioneer NEX8200. You can use a lot of different units today as a few companies now make the plastic surround trim pieces so the unit installed will look pretty much OEM. As mentioned, you can keep your stock speakers with a MOST adapter. If you have steering wheel controls you can keep most if not all of them too with another adapter. Go to Crutchfield and put in your options as a start. You don't have to purchase it all from them but it will give you and idea, they do have great customer service. I would stay away from the cheap no-name Chinese units and stick with Kennwood, Pioneer, Alpine, etc....

 

 

I'll also throw out that there was a rumor the Bose sounded better with many aftermarket stereos than with the OEM PCM unit. After my Pioneer install I think the rumors are true, it does sound better now. I'll also say that I chose the 8200NEX because it is one of the Pioneer top of the line units for a decent price. It does have stand alone Navigation that I wanted as I live out in the country and lose cell phone coverage in some areas so Navigating with Cell phone Bluetoothed (Apple maps, Google maps, Waze) wouldn't be reliable. When I'm in the city I'll use Google or Waze sometimes but the Pioneer Navigation is pretty good. There are lower priced units from Pioneer, Kennwood, etc... that don't have stand alone Nav, you can just Bluetooth from your phone to the unit (Apple Car play or Android), this option just wasn't great for me. The harness for the Pioneer Avic from Crutchfield (Scosche adapter) wasn't a straight plug & play, it took a little splicing to work. I used all wire taps so I could always covert back to an OEM if I wanted although I never plan too. Mark

 

Been at least two years now since I did the Siecane 9" flat screen head unit replacement. I bought the most adapter with the unit. I did not need a new amp, my balance and fade worked fine after installation, as did my steering controls with the appropriate adapter. The sound was at least as good as the original head unit, maybe better though the greatest deficiency in the original equipment is the sub. I replaced the sub and am completely satisfied. I would love better speakers all around and some added volume, but it's perfectly acceptable. I'm glad I haven't had all the problems I've read about in various threads.

 

What make/model MOST adapter came with your system that allowed you to have fader control?

 

I wish I had a more authoritative answer for you, but simply it was the cheap, chinese MOST adapter that came with the unit from Siecane package purchased before I'd ever read to expect 50/50 failure rates on them. I just bought the optional MOST adapter with the unit and gave it to the best local stereo shop and it came out working fine.

 

I'm currently searching for a 955 and intend to replace the entire stereo system on whichever model I find. Still have a few questions after reading all these threads:

1. Of the four available stereo versions, are the two Bose systems the only ones with MOST and fiber optic connections?
2. If I replace both the head unit and amp to aftermarket, will I get error codes? On all four stereo versions?
3. If error codes are set from #2, what is the fix, given I'm not using a Dension or Mobridge converter to retain the stock head unit?

Thanks!

 

 

I believe so. My '05 was non-Bose and I just swapped in a new aftermarket head unit with a standard plug-to-plug wiring harness. The steering wheel controls required a separate control unit.
Are you sure it's the antenna and not the head unit? I get great reception with my JVC head unit using the stock antenna.

Did you replace the CDR-23?