I just installed an F900 in my Mk IV Golf - dude - what a b-ugger to find an install kit. I ended up buying two different versions off eBay UK. One was 39 pounds ($58 US) and the other 15 pounds ($25 ish). Shipping was though the roof on both. The cheaper of the two was my fav and the one I installed - will post pics if requested. Type this search "FP-17-00 Volkswagen Bora Caddy Double Din Facia Panel" on eBay.
I still have this fit kit - "VW VOLKSWAGEN Double DIN Fascia Fitting Kit CT23VW03A" - will sell for what I paid for it plus shipping.
I also ended up using a CAN-BUS adapter and an amplified antenna adapter - lots of wires, but all in all a good install.
Let me know if I can be of any assistance.
Scott