dom: this photo shows the faux grill that was on my valiant when i bought it. i thought it looked funky so i put an original grill in it and it slowed down a tenth so i ended up putting it back in. another racer i know had a 69 charger that he raced and he experienced similar events when he put clear plexiglas over the grill area of the charger. seems the setback grills catch alot of air. maybe you can fab some plexi thta is removeable for street driving? dave