I can't tell you the size or the spline count but it will not fit. The Scirocco wheel itself is a 380mm Petri foam wheel, but the hub and button are different.
If you got a Scirocco wheel cheap enough, you could address the hub issue by modifying another hub (drill and tap) or buy ego bgo's copy on ebay and then use a momo style button for a reasonable clone.
The Scirocco wheels aren't always cheap though, the early water cooled VW guys like them too.