We went to a local, recommended tire and service center for new tires and also had the transmission fluid flushed and changed. The mechanic noticed something broken so I took it to the Mazda dealership a few days later as it is covered under warranty. While there the Mazda technician told me my transmission fluid was dirty and should be changed. Our CX-9 has 50k miles on it so it might not have needed to be done at all but someone is not being honest here. Either the fluid wasn't changed by the local mechanic or the dealer technician isn't being truthful that I need it to be done. I wanted to check the color of the fluid but it doesn't look like there is a dipstick to check and I read on another post that the transmission is sealed and can't be checked unless other work is being done. Any suggestions as to how I determine if the fluid was changed originally or if the dealership is wrong that it needs to be done?