Looks like a time attack car. The mount isn't reversible and I'm guessing is what you can get without going custom fab.
I think that’s why it’s designed the way it is. It’s mounted to the chassis instead of a body panel like most wings are.
With the mount point on that wing, he should also get some front downforce due to the turning motion. Measurable in oz's, but still.
Out west there is a fella named Corey Call... he does the same thing on a GS w/o the bags at Thunderhill on stock tires...lol
It was mounted to the chassis to avoid trunk lid/deck distortion at speed. Basically, higher speed, higher down force and the truck can distort and screw up your AOA (Angle Of Attack). Also, mounting lower and farther back, allegedly (not my quote or study) was claimed to have a higher mechanical advantage of down force to the point you needed to adjust forward to maintain down force on the front. Gives another tuning option I guess.
Wasn't there a viral video of that a long time ago? I swear i remember that but cant find the damn video.