detached wing/spoiler above rear window?

[IsaacCarlson]

Since the rear window of most cars is at a steep angle and do not flow air well, would a detached wing/spoiler help direct some air down to reattach to window/trunk? I saw that flow viz with the det. spoiler and just thought i would ask.

[MetroMPG]

Assuming you're talking about this sort of thing over the rear window...



Yes, the spoiler will direct flow down the rear window (they use them to keep windows clear of dust/water on some cars), but at the expense of increased drag from the defector itself.

On top of that, it probably increases projected / frontal area.

[Hermie]

Not to mention creating plenty of lift...

[orange4boy]

I doubt that would create much lift. The angle of attack is much too high. Mostly just drag there.

[Piwoslaw]

How to decie whether to remove rear spoiler