Right, so I've asked for this previously and assumed that it was probably something that I had to wait to see until the New Year relating to replacement coupon codes for free car class upgrades on AVIS.

This is what a few minutes of searching has come up with:

United Airlines:
https://www.avis.com/AvisWeb/html/pa.../index_ua.html
- Free One Class Upgrade
- Free Day on Weekly Rental
- Earn Double United Miles
Reuseable, but doubt you can 'stack' the benefits on a single trip

Midwest Miles:
http://www.avis.com/AvisWeb/html/par.../index_mw.html
- Free One Class Upgrade + 1000 bonus miles

Delta:
http://www.avis.com/AvisWeb/html/par...2-22539-4240-5
- Free One Class Upgrade + 1000 bonus miles

America West:
http://www.avis.com/AvisWeb/html/par...2-22539-4240-3
- Free One Class Upgrade + 1000 bonus miles

Personally, I was hoping that Continental was going to renew their deal with AVIS but it doesn't appear to be so on their website. No matter, at the end of the day, it doesn't really matter which airline you're flying.

I usually use our corporate discount AWD code (can't tell you so don't ask) + AVIS Preferred number + a free car upgrade from whatever airline. I usually show them my AVIS card and present hte printed out coupon. This means I usually do end up standing at the counter for a few minutes while they get a different car for me but it's worth it since I usually got on 1-3 week business trips. I do /not/ want to end up with a Corolla or something!

Hope this helps some of you out. And Happy New Year.