[aerohead]

Originally Posted by freebeard

aerohead -- That's fine, man.

For the angle of the not-spoiler, look to that Mercedes Benz concept with the retractable boxed cavity.


https://i.imgur.com/W8TA6tA.jpeg

edit:
Whoops! I guess it's this Toyota patent from 2016


http://www.autoguide.com/auto-news/2...-car-tail.html

The next door neighbor had an extensible, nested pickup bedcover, similar to your tail.
Some would find the aesthetic off-putting, but the air would 'like' it.