[Phase]

Originally Posted by aerohead

The original spoiler conformed to a streamlined pathway, and simply extending it, at the downward angle it would project if you laid a straight-edge on the back of the car's centerline, theoretically, would suffice. Your up-kick design would over-accelerate the flow, lower its pressure, and kill it's direction towards the wake.
Below, just following the bottom of the rear quarter panels for the diffuser would put it at nearly an ideal angle for upsweep.
The August 2022 MOTOR TREND, PP. 70,71, has an article on the 2022, M-B EQXX. Mercedes-Benz is extending it's diffuser back almost 8-inches, while dropping down 3-degrees, above 35-mph, for a 10-count drag reduction.
I'm not trying to be a buzz-kill, but I see 'trouble'.

What’s trouble with the eqxx diffuser? I thought it reduces drag