GT Wings, Trunk Spoilers & Drift Spoilers
Between a spoiler and a wing, the difference is not a matter of style: the spoiler extends the bodywork and modifies airflow at the trailing edge; the wing is an airfoil mounted on struts, in free-stream airflow, and generates genuine downforce.
Downforce can be adjusted
An adjustable-angle GT wing is only useful if it is adjusted. Too much angle creates drag and slows the car at the end of the straight without adding useful grip; too little, and it serves no purpose. And rear downforce without front downforce makes the car understeer - balance must be considered across both axles.
Mounting: the point we overlook
A wing pulls hard on its trunk. Load-distribution plates and backing plates are not a luxury: without them, the trunk sheet metal flexes and eventually deforms around the drilled holes.
On the road
A wing that extends beyond the vehicle's dimensions or has sharp edges is grounds for failing the roadworthiness inspection.