A spoiler is defined as a device which has air passing only over the top of it and in your case, could probably be secured to the bodywork. An airfoil or wing is defined as a device which has air passing over the top and the bottom of the device and must be secured to the frame or rollcage structure.
NHRA 2008 Rulebook; E.T. Handicap Racing, page 105:
"Bodied vehicles: Non-OEM airfoils permitted, must be permanently attached to frame or roll cage, non-adjustable during run."

Just so you know, a Top Fuel wing is 1500 square inches. Side spill plates must fit into a hollow 22" x 22" square box.