The Bottom Line for GTR2?
If the words "No CD" mean anything, search for that quote at No Grip.
Xenon Headlights by Spuddy (or equivalent... also at NoGrip)
Super GT 500 mod v3.0 (at No Grip.. again)
Tracks... I'll leave it up to you, but Lemans, Sebring, Mid Ohio, Fuji... by VLM: all best-available versions IMO.
For the Simbin titles, GTR2 and Race07 / GTR Evo / Race On -and-the-addons... in case it hasn't be obvious, No Grip Racing is an outstanding source.
I'd agree that GTR2 is the most complete off-line sim-racing title available. That's a semi-sad statement given the release date.
GTR2 is also not-so-good for on-line racing, which is where rFactor shines. (Get both... at least.)
