the Zonda will be built in a few more than 100 units units within 4 different engines up to now (considering the original one with the MB 6 liters, the enlarged version to 7 liters, the new 7.3 of the S and F and the upcoming Cinque and the 7 liters from the CLK-GTR) at least 1 million dollars per car, even if the actual price is closer to 1 million euro. the car is hand built, for real and I can guarantee since I visited both the factories, based on your requests, and it comes even equipped with a pair of shoes and a set of two luggages of the same leather of your car. the factory consists of three rooms and is smaller than my parents' house, you can meet the owner and founder while visiting it and he would sign the model of the car you will buy if you ask him. I did so, but he left the building for lunch just a couple of minutes before.
the Murcielago costs about a quarter and will be built built probably in more than 5000 units with just a mayor restyling. The factory is pretty small for such a big manufacturer, but it's still a big factory, and even if the assembly line of the Murcielago is quite manual if confronted with that of the Gallardo, the assembly of the single parts isn't so. together with the Gallardo models, Lamborghini has a huge parking lot behind the factory with more than 300 cars parked there in every moment before of the delivering. check google earth.
not discussing the "supercars" definition, which actually doesn't exist, but you have to admit they are two different kind of "supercars".
Maybe the Reventòn is a true supercar, but I can't stand the fact that it is a re-bodied Murcielago at four times the original price.