Let me clarify. Roush did batches of cars from Ford. These batches could be anywhere from 1 to 100+ cars at a time with sequential VIN numbers. So they got batches of cars in all the time throughout the year. Yours was in a batch of 45. Your batch had 17 blue cars (I can only verify that 3 for sure were sonic blue, but I suspect most of the 17 were). All told there are supposed to be for 2005 a total of 330 blue roush mustangs of which 247 were sonic and 83 were windviel blue. I have not verified this overall split and I actually believe it may be 331 total blue mustangs.
batches keep going til you get to about 2050 or so.
So batches vary you get the idea. I can tell by your VIN if you have a real roush or not. Another way is if it lacks the white faced gages that is a big tell tale sign it is not a real roush. Although some of the earlier VIN numbered cars lack the white faced gages so it is possible to have the stock black gages (I'm guessing maybe a 50 total cars came without white gages) and of that I would say 90% of those would be the earlier cars (hence they would have forklift holes) so if you run across one without forklift holes and black gages I would almost bet it is not a real roush. Just got to do the research, because with these cars there are exceptions.