even at 130, i got up to like 150 racing my friends ss, and had no sway or anything. As fas aerodynamics, i believe alot of difference exist. I personally have never seen a Saleen race on a track, nor have I heard of the kit helping all that much. To me, the kits people get on these Saleens are a combo of minor aero, and major looks. If doing 130 or so on the freeway is all ure concerned with, you would probably be ok with just that steeda aero wing, it is low profile and looks cool.