I have never tackeled one of these myself, but I have read that you can expand the clamp by placing a muffler clamp inside of it and opening up the clamp.  You have to re-arrainge the clamp so the nuts open it, rather than tighten it.  It seems like this would work, especially if you filed the top of the clamp flat to make it less likely to slip off.

Whatever you do, BE CAREFUL.  These clamps are very powerful.  I wouldn't want one flying in my face.

If you have any more Rabbit questions, check out the Scirocco list (info is at www.scirocco.org).  While it is a Scirocco list, we welcome questions about any of the A1 chassis VWs (Rabbit, Cabriolet, Pickup, and Scirocco).  Its kind of like the Vanagon list with more talk about racing against Hondas :-)

Bill
-------------------------
 There is a tool for same.
 $25 from on-line vendors. Without the tool, it is a grim struggle ending
 only in sorrow.