just wondering wat is a NOS modification.heard it helps with the 3ROD prob.hope to get enlighten on that part 

is the 20gb on the premium package expandable to 120gb?is the hardisk external or is it already built in =(..is there any external hard disk for the 360? was wondering bout this coz din wanna get the elit version coz i personally don like the black xD prefer the finishing in white hahaha

thanks in advance for the info^^

cheers~