I think you do need a pectal board for water injection, but I'm not 100% sure. I will be hooking mine up in a week or two. Basically one wire from pin 12 (I think) to a relay to two washer pumps inline. I think the SECS monitor is the same way with wire to relay to two pumps. The diagram is in the rally manuals (which i think are still online somewhere).

You can get the spray jet from Mountune for 10 pounds too.

Cheers