GTP_CargoRat,
Less you know, better you sleep
Yes, i can load hacked save on non-hacked PS3 and go online with any car i've opened. But there is high risk to be discovered by PD and get a ban. It fully depend on PD. If there will be cheaters online then ban wave will sure follow.
So, from some point of view you are right about online. But only from some.
I don't know where are you getting information, but hacked PS3 can access PSN already around 1.5 month.
Lewis_Hamilton_,
yes, there are additional hidden tweaks:
1) 2 additional engine tunes (5 in total)
2) 2 additional turbo stages (5 in total)
3) Clutch: Triple-Plate
4) Flywheel: Racing
5) AYC Controller
6) Large Diameter Rotors + 4(6,8) Piston Calipers
7) Ceramic Carbon Brakes, Brake Balance Controller
8) Tires:
Every kind has 2 types. Like Comfort Hard (C), Comfort Hard (V).
Also, there is Sport Super Soft and Racing Super Soft tires.
so totally 22 types of tires! 8-O
9) Nitro upgrades
10) Additional power improvements (5%,10%,20%)
This is only list of features. It's not exactly implemented in game.
With so many hidden tunings, it's easy to make GT6 from GT5 already, haha
Probably, PD is testing some new features already. May be it can be unblocked by some special key file, save, or whatever.