What features are absent from the '04?
 

Back-up camera? Keyless entry? Keyless start? rear climate control?

Most important
 

bluetooth. Oh, but it has OnStar, but that doesn't work.

I don't think Canadian cars have OnStar and I don't own any bluetooth devices. So far so good.

Rear Climate control was an option on the '04
 

Also, the leg extension on the front passenger seat was not an option on the '04 - only for the driver.

No back up camera until 2007; better graphic representation around 2006 I think

If your cell is not bluetooth then look into it
 

I would say it is the best add on to any car. Worth looking at a late 05' for it

Re: I don't think Canadian cars have OnStar and I don't own any bluetooth devices. So far so good.
 

I'm with you as my cell phone (company provided) has no bluetooth thingy. I have a corded earpiece/microphone and it has speaker phone & voice dial. I think I'll keep my '04 as it is paid for. Last Audi went 286k before being donated to charity. I'm looking to get 350-400k miles out of this one.

Bluetooth can be added to an '04 with OnStar via BMW btum if needed

yes,yes,yes,not sure...but you can turn off TPMS in MMI if not upgraded...