I actually ran into this problem while in Huntsville for the Huntsville/Nashville Meet. I had some problems on the way to Huntsville that Friday and it finally gave out on me that night. The following morning, I ran it a few miles up the road and came back to check the level. Well it read that I was about a quart low!! So I ran to the store and grabed a quart and threw half of it in. Road around the parking lot a few times and allowed it to shift through all the gears a time or two. Came back to the rooms and check it again. Now I was over full a quart!!! I was so frustrated at this point, I asked LoCoZ (Hector) if I could borrow a 1/2" drive rachet so I could drain it out and start over. Now I was frustrated and embarresed!!

Anyway, to finally get a good reading I ran over to a local gas station and pulled up to one of the pumps, like I was going to get some gas. These areas are always known for being level since they are replaced so often and they have to be because that is about the only time normal people check fluid levels and such.
I found out that I had drained out too much so I threw some back in and got it right. Drove around and came back to check it again, it was finally constant!
Make sure that the area that you are checking your fluid is level and that the car is warm. Run it at least a good 12 miles before checking the level. As for doing the "4 quart drop" always raise the car a little from the front. This will allow you to always get out all 4 quarts. If not, then just add 3 quarts and check it. From there just top it off as needed.