YES! It is a direct bolt in! The ONLY thing you might run into a slight issue with is the brakelines. You'll have to make your own flex lines somehow from the uni-body to drop down to each wheel. this isn't a big deal at all though.
*Drop out stock rear suspension (springs, shocks, quad shocks and brackets, upper and lower control arms, axle, unhook brake lines, ebrake cable, and ABS (if equipped) sensors). The ABS sensors are unhooked by lifting the back seat and finding the harness where it comes through the floor and unhooking it there.
*Take the stock solid axle and remove the pinion flange. You have to re-use it on the new IRS. You'll need the entire rear suspension cradle from the Cobra donor car, cobra shocks, cobra springs.
*Take the entire cradle and bolt it up! You might have to wrestle with it a bit but it WILL go in!
It took me and a friend about 10 hours total working time to swap the rear ends between two cars.