Yeah, because rehashing a Caprice 9C1 was such an exclusive design.
And the current 2014 model is easily the best looking Impala in decades.
Oh, and Camaro is derived from the same platform as the VE Commodore. It's not as exclusive as you think. In fact early chassis IVERs used modified Commodore bodies. If you want to talk exclusive engineering, look at Corvette. And even then you have some trickle down programs to other vehicles (MRC, Gen V V8s, etc).