I suspect the IRS was held back so the SVT group can make the chaching(!) from the spendy customers, while adding IRS might bump the regular stang one or two thousand, which might have been above the spending limit of the targeted customer according to some unrealistic market study. All the while, FoMoCo makes the excuse that the live axle is a "beefier" design aimed at the drag racers.
Lots of excuses coming out of Detroit...they need to do like the Japanese car makers do..beat the piss out of the project manager(s) and disgrace him/her in front of his/her home town if they fail to produce!
