The drivers door is an integral part of the frontal armor, but is limited in thickness due to its being a hatch, ive found that lobbed rounds (say from 2400 or more) hitting this area are likly to destroy the tank outright. close up works to, though its rather fickle at medium ranges.
I do know that since that frappin sherman came out, that theres nowhere to hide when one is around, and t34's just aint got the guns to deal with one:cry