For the 2006 Audi A4 - has anyone compared the standard audio package versus the optional Bose audio - Is the Bose upgrade worth the extra money?

The Bose sounds better, when everything is working. If you have a problem, they cost more to repair than any other audio system on the market. They have a closed operating system and parts will not interchange with other brands and mostly won't interchange with other years or different models of the same year.

I have an older Audi that had a Bose cassette unit. The only way to upgrade was to take out the head unit, all the speakers and wiring. Then replace with an all new system. At $600.00 installed, I got a better sounding system with CD, MP3 and USB for less than the price of one new Bose amp. (Mine had 5 amps, 2 bad.)