If anyone is interested, here are the AWD codes I could not get to work. I didn't try all possible dates, rental locations, etc., so it could be that some of these may still work. Most, if not all, of these I got from the old list in this thread originally posted by MartinElk.

D331000 is definitely invalid.

A153700 Avis employee rate
B900000 AAA
B973000 Gusto Card
D005297 Amateur Sports Assistance Program
D086689 American Association of Engineers
D086533 Marshall School of Business (USC)
K163324 Florida Space Coast Golf Association
J098440 Canon
K774100 Avis Online Discount
K860600 Starwood Preferred Guest