The rear end is a bunch of stuff out of the parts bin, with a "We got to make this fit" subframe around the whole assembly holding it in the car. Nothing about the rear end is "engineered," it was made to put in the car to say it had independent rear. It doesn't take a rocket scientist to look at the ghetto ass IRS in the car to come to that conclusion. If they wanted to do it the right way, the Cobra unibody would not be identical to a V6 Mustang unibody. But hey, if you're happy with a rigged IRS vs. no IRS, more power to you. Fact is, the SRA will always work better in this chassis because it's what was engineered for this chassis.