-As stated, the MonthDayHour is on the door sticker. But I think you're asking if you can get that from the VIN? Don't think so, maybe?
-The cars are not nescesarily built in sequential/numerical order, ie: one after another with 500048 following 500047, they may not roll off one after the other at the end of the line, but I bet they'd be close. At least that used to be true during the GenI and II days.
-Eg: my vin ends 0341, it's a March build date, they built like 2000 that year, so I doubt they'd only be on 341 by March. My brothers car, built the same day is 22 apart on the vin, according to the MDHs they rolled off within 4 hrs of each other, his at 8am mine at 12pm. (keep in mind they make maybe 8 or 10 a day, on average) If they were sequential, you could extrapolate that they may have made 40 or so that day, but that seems highly unlikely. I'd be willing to bet that they were only 2 or 3 (at most) apart at the end of the line.
Maybe someone has some more recent anecdotal evidence.