On this I agree with eaglefly, his post a few back is fairly spot on.

Does anyone think it is possible to follow the 8 hour rule (with some self control prior to the 8 hour mark) or further the AMR rule of 12 hours (again within reason), and still show up .04 or more. Further does anyone think it is possible to follow the above, and WAKEUP FEELING SOBER, and show up and find out that your not? I heard once about someone who drank heavily, but followed the rules and rules of reason, but had it so built up in their system (over years), that they got hit with a random test almost 20 hours after they stopped drinking and still blew above .04 (after a 6 pack 20 hours prior, nothing super extreme)....Does that even sound possible.