The rear wing / spoiler could have been helping you, but probably not much. At best, the air behind our rear windows is rather turbulent. I noticed after 120k that my struts were getting soft, and the rears were pretty well shot. At highway speed, the car lacked stability, and the rear bobbed horribly under braking. I got a set of KYBs from SPS and, with an alignment, it is rock-solid again. I'd check your struts before you give too much credit to the rear spoiler.
I don't think spending energy on the wiper area will bring you much tangible result. Per reading, posts here, etc., I'd go after a flat bottom, flat wheelcovers, front wheel deflectors and the like first.
I'm registered on Saturnfans (Bman91SL2), but I'm not there much. I owe them a post because I tried a Marvel Mystery Oil flush and cured my oil consumption problem.
Bman
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