[Angel And The Wolf]

I've been told the optimal lower angle on a boat tail is 2.8 degrees. to prevent separation of the air from under the car as the car/tail passes through it. The problem is that on extended boat tails this leads to the dragging of the tail when crossing from one grade to another, such as entering a driveway from the street. If only one could raise the tail out of the way temporarily. If one could mount the tail to the rear of the car on two rack slides with fairly vertical electrically driven screws, and flip a switch on the dash.... Well.......