After reading almost all the posting on this site about CX-9 hitch I finally decided to go for u-haul hitch. This is the same as Valley hitch but OEM and rebranded by u-haul.
Here's the link for the instruction on Valley by etrailer.com:
http://www.etrailer.com/instructions.aspx?pn=V82592
If you look after the model number on the instruction there's another number 78223 this is the model number that u-haul is using.
Heres U-hauls site and search for Mazda CX-9
http://store.uhaul.com/Hitches you will find on their web site the part number 78223.
If you don't mind having u-haul sticker on the hitch and your application is just for bike rack I think you can save money from u-haul.
Mine will be install on Wednesday, for CAD$204 including tax and installation I think its a good deal. I don't need to worry about shipping and they will guaranty the installation too.
The only thing I don't have right now is the information about the wiring diagram for the hitch wiring connector located on the driver side tail part of the car.
I hope someone with original Mazda hitch wiring can post a picture showing how their hitch wiring is connected.
But in your case I guess you don't need it because you just want it for bike rack.