As for the push-through of the wheels, I think that's just a result of an incomplete version of the game, without the later refinements to the physics and suspension settings.
A good example would be the Lancia Stratos and Stratos Rally Car in GT3. I added them to my garage through MK's program, along with a couple hybrids, and the Lamborghini and Porsche. But those two Stratos's are clearly not "finished", as they have very bad push-through on every turn and whenever you hit the brakes. My guess is that they were scrapped earlier in development, before all the refinements had been made, and were buried in the code in their incomplete form, never meant to actually be driven. To my knowledge, those are the ONLY two cars in GT3 that have any "push-through" errors. We know how much of a perfectionist KY is, I doubt he'll let that slip in the final version of the game. Prologue, Concept, all the demos.. they're all incomplete builds, not exact to the final product, and I'm confident all that will be fixed in the final version. The Stratos will probably be the best way to test it on the final game, since that car has a very shallow wheelwell in the front.
As for the segmentation on the wheels... There's no way around that. They can only use so many polygons for the in-game models. To make the wheels perfectly round with no visible segmentation would mean they would have to have hundreds, if not thousands, of polygons per wheel. And that's simply not an option. If you really need to see it, I can whip up a low-poly and high-poly wheel in CG to show you the difference.
