I am only familiar with RC1, as that's what I have in my car having been told by Jeff that RC2, in all likelyhood, was too much for the clutch in the 5 speed Jetta, if it were pushed. I find RC1 to be really great. Rarely do I use it, but when it's necessary...stand back!!
In a Passat I suspect RC2 is perfectly OK, even if driven hard, (I haven't researched it,) but I'm not into that nor would I prefer to have a car that had been driven hard, which is the reason I said RC1 would be OK...not to make anyone wrong for having any RC's be they 1,2,3 or even 4 which I think I heard about someplace.
I am finding this Passat car search interesting. There are a lot of great cars out there and great drivers to go with them. TDI'ers are one of a kind. I have met some great people just in this brief search. (Not to mention the many I met at the '05 TDI Fest, on the road and monthly meetings in the Chicago area.) If it is ment to be the right car and owner will appear. I'm just putting the word out...and yes, I know I missed a really great one, but it was the wrong color for the skirted who sits in the navigators seat, if you know what I mean!!!