I also put a kury rack on about 3 years ago and use there rack bag on it been very happy with it if you would like pm me and tommorw i can take a pic and show you !
I've got the bag too and am VERY happy with it. The built in (attached by a tether) rain cover is very heavy duty, and kept the contents dry while on vacation riding the BRP this summer. You can store quite a bit in it, and it's got "easy access" pockets for the passenger, as long as the rain cover isn't on.