We are thinking about running the Scirocco at rallycross. I have a set of all seasons that are on BMW bottlecaps that I was thinking of using. I figured those will be better then the Azeni RT615Ks. The suspension is using very stiff Neuspeed race springs which work great on autocrosses but will we be beat to death running it at rallycross?
Only one way to find out.
It all depends on the course where you run. Some are very smooth and you will be fine...others not so much.
If you are on the facebooks do a search for "Dirty Dori." The owner is in Alabama and he may be able to give you more insight on the site conditions and how well the spring rates would do.
We ran a MK I Scirocco for a few years at our local rallyx scene. It had Bilstein HDs if I remember correctly, they were pretty damn stiff. The tire of choice for our area was Dunlop SP60. They were tough and really grippy, and cheaper than a true rallyx tire. We ran tubes in them.

was that rocco Greg Olsen's old car?
My RX7 is on spec7 road racing suspension. Not crushingly stiff, but stuffer than one would usually want for RX and we do fine. Our sites are rather smooth though. Other posters are correct that you should find out what you can about the site.
In reply to captdownshift:
Not sure if that question was for me or 93EXCivic, but we got ours from a guy named Dan. 
If it's the one that i'm thinking Ed and Marshall have also owned it, the car if it's a 77 that's made it's way through the WDCR autocrossers about 6 times that's the girl.