Hi Justin,
Mk I's do "squat" a little at the rear. If you wanted the car a little more on the level you'll need to bring the front end down, this does however tend to throw the back end out more, fine if you've got good reactions. I think VW gave it the stance that it's got purely for the reason that there is no weight in the back and therefore putting it closer to ground keeps it in the direction it's supposed to be.
Just a small extra note most Mk I's built/modified for quarter mile are higher at the rear to get more traction on the front, they don't have to go around corners to much though!
Hope this helps, Michael