Ok...thanks for the replies people.
From what many of you guys have said, it's simply to do with the affect on the wing aerodyamics.
Volume ...surely the violation of the area rule case (Sears Haack approximation) only affects high speed 'sonic cruisers' and not the more ocnventional things flying about?
The reason I ask, ironically, is that we are designing a sonic cruiser as part of our 3rd year Aero Eng course at uni and am trying to work out where to locate the engines! So form here, it looks like working out all the cs areas to approximate a Sears Haack body?
Cheers
Jason