The 99 Cobra was the first Mustang w/ the independant rear suspension. the 2000 Cobra R, the 2001 Cobra, and the upcoming 2003 Cobra all have variations of the same basic IRS. No Cobras have ever some from the factory w/ and automatic trans.
I have spent considerable time in all of the different Cobras that have the IRS. What do you want to know about them?