I believe that shabbat, per the torah, doesn't actually start at Shkia and that this convention is a gezera to avoid a makhloket of the real start time.
What are there parameters of this discussion?
What is the closest to shkia this "real shabbat start" could possibly be ie earliest case by earliest opinion? Immediately or Would it be R' Yehuda's opinion of aprox 12 minutes?
What issur would occur if one violates shabbat a couple minutes after shkia? For example, if one is stuck in traffic and chooses to continue driving for a couple of minutes after shkia rather than ditch their car on the side of the road.
