Stock SVT:
No wing except the factory one...which is pushing it.
Modified SVT:
Wing has to go along with the car(ie Exotic paint, big chrome wheels, extreme lowering, etc)...if it doesn't fit the car it just looks ridiculous.
Unless you frequently have your car in a wind tunnel to test its aerodynamic properties and have the wing made to enhance/improve the cars stability at high speeds...then thats okay too...but.....