Yes, the M3 comes with 18's, and maybe there is a 19" option. But the M3 is to the 3-series what the Cobra is to Mustang. The M3 rides extremely harsh, and is tuned for the fanatical enthusiast, who wants extreme handling. I don't think the GT should handle "bad", or that handling is not very important. But in reality, even with the 17" wheels, it will probably be a super handler. My point is that the majority of those in the market for the GT would not accept BMW M3 ride harshness. And the GT is NOT an M3 fighter, it's mission is a balance that is more toward the mainstream market (rabid speed-freak Stangnetters are not mainstream, trust me, we're lunatic fringe). I swear, I think the majority of the bitching on this forum is caused by the fact that Ford is releasing the GT first, but everybody's expectations are "Cobra" (although few here want to pony up the dough for a Cobra).
"Where's the trick hood"
"Where's all the scoops"
"Where's the more aggressive body styling"
"Where's the 19" wheels"
"Where's the 6-speed"
"Where's the IRS"
"Blah blah blah..."
The GT is not positioned in the lineup to be the holy grail of Mustang performance. It's supposed to be a great bang for the buck, great handling, great sporty looks, and easy to live with for a large segment of potential owners. And Ford will sell a TON by sticking close to the formula. If you want to lower yours, upgrade to bigger and fatter wheels, and so-on, well...... what a concept. MODIFY your Mustang!! Not to mention I'm certain an 18" wheel option will be forthcoming, if you'll just quit holding your breath and shivering, and just wait a bit. You guys just have ZERO flippin patience. You want everything, NOW, as if the design/engineer/manufacturing process involves a wand, a robe, and a top hat. If I see another "how hard could it be?" I'm gonna puke. Believe me, spend 15 minutes with a real automotive engineer that works for any of the Big 3, and you'll realize it's crazy how much work they have to do. These guys aren't "bozos". I'd be willing to bet that if a Ford chassis engineer came on Stangnet, that they could summarize the reason the 18" wheel option is delayed, and everybody here who's been moaning would sit back and go "Oh, wow, I hadn't thought of that....". They've obviously got something delaying them or giving them fits. Better they work it out, rather than just say "screw it, just bolt the 18's on the cars".