How much work is involved in making the adjustable rear spoiler change position when the brake pedal is pressed?

Was thinking of something similar to the new Mclaren Merc.

My 22b replica spoiler has an adjustable fin and i thought that it shouldnt be too difficult to make it adjust with some small solenoids when the brake pedal is pressed, thus assisting in the stopping of the car with the increased drag.

Nothing maxpower like just a slight subtle movement to increase the downforce on the tail.

Chris.