I maybe wrong but doesn't the fastest accelerating production car have a live axle?
Ford Mustang Cobra Jet 2010!
From Wikipedia "A drag racer took his completely stock car and recorded a 0-60 of 1.52 seconds and a 0-100 of 3.26 seconds, and made a 1/4 mile pass of 7.848 seconds @ 174.4 mph, crowning the Mustang Cobra Jet as the world's fastest production car, smashing the Bugatti Veyron and Ariel Atom V8 by nearly a full second in both categories."
I have driven the mule and would have put the new suspension on my roadster rather than the suspension upgrades I fitted to my Roadster.
IMO designing an IRS system would need a different chassis as the strongest part of the chassis would need secure the diff or require adding so much weight to a trad chassis it would negate any benefit.
