The last company I worked for did a lot of printing for the automotive industry and they did some poster work for the GT. I scanned through the hi-res images and I think the low stance and cooling duct-work are the only things I liked about it. When I saw one in person parked on a street in Manhattan, I also liked the clear engine cover. That's about it. It's too Lamborghini like for me; too many angles, not enough curves.
Back to the OP, I think if a full skirt is (for whatever reason) infeasible, then a dam might be the way to go. It'd need to be fully tested to make sure that the increased frontal area is counteracted by the reduction in wheel-well drag.
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