I don't think it's as dire as you guys paint it, but yes, I would make changes. The front-to-rear depth of the wings, or at least the endplates, should be reduced significantly. The rear wheel guards should be removed, or at least cut back a fair amount. Get rid of the air box bulge. And make it a low nose.
If we're going for a more conventional idea, look at the 1994 or 2000 CART machinery.
If we're going to do something more "out there", but that I could still call attractive, I think I've found the best example out there. This page has a rendering of a concept that is significantly based upon the Interscope Batmobile that was driven by Danny Ongais at Indy in 1981.
http://www.motorracingblog.nl/?p=3831
It's sharp and sleek. The bodywork is pretty simple. The wings are fairly minimal. There's enough space in that envelope for adequate crash protection. It's striking and looks fast even in a still image. Heck, it even has plenty of space for sponsors to put their names/logos.
I'm guessing that the original Interscope car had some input from Porsche designers, with that long tail, before the Porsche Indy Car program was scrapped in 1980.