A few days ago I noticed my 2007 Mazda 3 felt like the brakes were dragging. I took it into the shop and the mechanic replaced the front brake rotors and pads and sent me on my way. The problem seemed to be gone. A few days later I noticed the same thing happening again so I took it back to the same mechanic. He lifted the car for me and spun all the wheels to show me there was no drag. When we went on a test drive for me to show him we both noticed the car glided smoothly when we were driving down the road and the gear was put in neutral, the way it felt a week ago. When we put t back into drive gear, the car immediately starts to slow down as if the brakes are gently being applied. He said it is probably a transmission issue but he doesn't work on transmissions. Any mechanic I call in my area doesn't want to work on the transmission. What do I do and has anyone had this problem before? I have 170,000 km.