? What is the value of the screen opening at the rear of the S2?

[Richard48Y]

I am thinking of something like these pics.
Basically a flat extension to prevent air recirculating over the rear of the engine cover.
Not really intended to create downforce.
Probably needs to be at least 8" deep and full width to be effective.
I may try this on my spare rear cover for particularly hot days, or competition events.
A tuft test to follow of course.

[RonPNW]

The rear opening, unfortunately, allows engine compartment air exiting through the cover vents to flow back in.  I wouldn't glass it in though.  Just fit a clear cover.  That way you maintain the stock appearance and solve the air recirculation issue.

That is a good point. Further, I can test with and without. I'm going to go with a removable plate.

My plan already includes rear wheel spats (a small air dam directly in front of the rear wheel in line with the wheel arch). the hope is to increase the airflow up, through the engine bay, to get a little more engine cooling and cool air to the air filter. If this works, it should also increase the air pressure in the engine bay and possibly get air to flow out of the rear grill. That should cool the exhaust components and trunk. All speculation at this point.