Oh, stall us out on the "crummy AI" deal. I think we all realize that the AI is a b**** to contend with, but this is a broken record.
By the way, nice point, my fellow Texan h0ss. I think PD was working with a certain game engine and couldn't really manufacture such a shift in time. But don't fret. Chances are, we may see GT5 with the same driving physics, but a new graphics engine which features (but is not limited to) cycles in time, cycles in weather, maybe some damage (I heard it's possible with GT5), and maybe address all the issues GT gamers have b****ed about for GT4.
I think this can be done. My one real concern is about how you go about adding different lighting styles to buildings and such. I think if PD wants to examine day-to-night-to-day cycles, I recommend the Grand Theft Auto series. Play either Vice City or San Andreas and note the cycles of time. San Andreas does it a bit better than VC, but either game is good to use. There may not be realtime shading and reflective mapping, but it's nice to see day turn to evening, then night, and all the way back to the morning and afternoon.
PD's going to have to study this from other games, or if they can't be stopped, they can try making such time cycles themselves. And also, maybe look at Vice City and San Andreas and MotoGP 2 about weather. I wouldn't mind one or two more ice racing tracks for the next build, so snow would be cool. Okay, this is probably going to end up a wishlist, so I'll chill for now. Meanwhile, enjoy the fighter jet effect.