The value of the 2nd hand roccos will be dependant on supply and demand at the time you sell. At the moment 80's Fords (which were worthless in the 90's) are fetching more than much more powerful 90's M3's and Porsches, just because there are shed loads of the latter...
If I was looking at this sort of car with this much potential power I would only go one way, S3. There all FWD and no matter how good a diff you have the 4wd will be better all round. S3 with remap is where my money would go. Classier than the other two.
I love the look of the new RS!! and for only 25k its silly peformance but useable every day too... ..........25k!!!!!!!!!!!!! still a lot of money for a car.I would go for a mk5 & spend a bit on extras .
I had a look on the audi site today and the S3s are a fair few quid more than the rocco, plus they look borning! they dont look special enough bth and unless you know what you are looking at they just like like all the other S line A3s out there. I also had an email from VW saying the rocco R20 is due to be on the road in Jan 2010!!! so it looks like I have a long wait [:^(]