i know there was some talk about this a while back....auto upgrades would be a great way of getting some space available in the lower classes....most of the trains on popular routes are sold out & getting a confirmed seat in difficult....i regularly travel between delhi - allahabad for work every month & there are 2 very convenient trains that leave at night & reach early in the morning in both directions....most of my reservations in ac first class are last minute & while i always manage to get a confirmed ticket in the end, i quite often see empty seats that people pay to upgrade to....