FYI - I actually bought mine from the Netherlands - CMS in Lelystad. If it's nearby you could save yourself the postage costs?
        
 
         
        http://www.cmsnl.com/products/fi-disgnostic-tool_9089003182/#.VPy7JPmsWSp
         
         They were, and still are, the cheapest place to get them from at 88 euro (�63.50 for those in the UK). A tool worth investing in IMHO - I've used it a lot more than I thought I would have done.
         
        
 OTR also do them, but for 100 euro plus delivery.
         
         
        
http://www.off-the-road.de/en/XT-660Z/Electrical-system-Lighting/Diag-modul-XT-660Z.html
         
         Interestingly, most (not all) Yamaha dealers won't sell/order you one... and if they do it'll cost you dearly!