In the second thread in my post above the front spoiler is sitting 4.5" off the ground at the center.
The drop is not that much. So far no real issues with the lowering this way. The big gap up front is gone if you look at the comparison pic's in Thread #2 above. The rear is a tad lower but no scraping issues.
IMO the lower you go the more you will feel the ride change. You also get that much closer to the bump stops. 1.25" in front is about what I would say the resonable max is, for my steep driveway 1" is about the best I can do to avoid a scrape.
Steve is right, my Vet scraped without lowering anything. So I said WTF and slammed it, replacement spoilers are $38. It looks great. Can't drive it anywhere, so the only time it gets driven is on the trailer to the track, or to the track. Promised I would not do that to the GT. I am happy and never concerned to drive the car for fear of scraping. But after the vet I am still in the habit of looking for the low risk entry points.
Front spoliers are not that expensive. If concerned, buy a back up.