There was at least 4 quarts (more likely 5 quarts, but a bunch missed and spilled on the garage floor, so hard to say for sure) from the previous owner. What's throwing me off is that the dipstick is bone dry. The only thing I can guess is the previous owner or a lube shop swapped dipsticks with another BMW.
I already checked the tube for blockage, but I can see light through it, so it's all clear.
Thanks for the measurement, I'll go measure mine to see.
-Micah