"It was available once and it was not a "draw" for additional customers. In fact, several customers swapped in a live rear axle because it was lighter and better for drag racing !"
And my response? "I've heard that before, but let's not forget that not all Mustang buyers will be going down the quarter mile. And don't Chalengers, Camaros, Corvettes, BMWs and even Cadillac CTSVs go drag racing? "
The promise of a 2013 IRS Mustang is nice, as is the increase in power, but even Hyundai's Genesis Coupe has IRS and the 2.0 Turbo 4 has 210 hp to the Mustang 4.0's 210. You can love Mustangs and still point out their lacking. That's how you improve the breed. You can't design a car for the 21st Century just to go fast in a straight line. Even though I've read great reviews of the new multi-link live axel's handling, it's laughable to excuse the lack of IRS at this late date.
And I say yet again, why no IRS for the Mustang?! I'll keep saying it until I'm blue in the face or there's an IRS under the Mustang. You don't design a car for the 21st Century using a live axel.
No argument or excuse is valid, period.