Here is a quick picture if I understand this correctly...



If the rules state that the size of the spoiler chord is a bigger length than the height it can be off the rear deck/trunk, then you must install the spoiler at an angle so it doesn't exceed the maximum height if using the maximum length chord. For example, my picture with the 45 degree angle.

If you tried to use maximum chord length (if bigger than height) and installed it at a 90 degree angle, it would exceed the maximum allowed height and be illegal. So to be legal for a 90 degree spoiler, the chord size would be the same size as the maximum height?

Now you could also mount the spoiler at a 0 degree angle to the rear deck/trunk and you would never exceed the maximum height.

If I'm thinking about this the wrong way, please let me know.