Roush Would the 99-04 S281 benefit from the product...

Unless you're actually doing some SCCA or road-racing, save your money.

The only suspension that is changed by saleen is the front swaybar, and the shocks and springs.

I recently installed the X-2 ball joints on my saleen to try and get a little more handling out for autocrossing. They work pretty well and gave my car more camber that I was looking for as well.

Just driving on the street I probably would see little benefit, and there are other areas of the car that would benefit from the attention more. Do you have full length subframe connectors, like the ones from Maximum Motorsports? Many people see these as the best bang for the buck improvement.

EDIT: I just re-read your sig and you have them already, d'oh!

Plus, changing out the ball joints is NOT fun!

The main reason I changed mine was to get the control arms level again after installing coilovers and lowering it a lil more.

The bumpsteer kit isn't that necessary unless you start running crazy caster, or go really low. I have the X-2 ball joint kit, and have noticed a little bumpsteer, but nothing too bad.

I would DEFINITELY get some good caster camber plates over a bumpsteer kit if i had to choose (I am very partial to the maximum motorsports ones). They have a nice bumpsteer kit as well.

If you like DIY stuff, Mathis's Mustang Performance Hanbook 2 has specs to build your own bumpsteer gauge and bumpsteer kit as well. I will be building their spherical swaybar endlinks soon. http://www.amazon.com/gp/product/1557882029/sr=8-2/qid=1141707924/ref=sr_1_2/103-4394462-4207013?%5Fencoding=UTF8