So I have a 2006 Mazda 3 S 2.3 Cylinder with 135K miles on it. I got it at 104K miles. A few days ago my dad did my oil change. I am certain he let out the oil (which is black/dark brown) and put new oil and a new filter on. After the oil change my AT light came on and it started shifting into 3rd gear really quickly while driving. He checked my ATF and my dipstick was bone dry. Same day we put 7 qts of ATF (requires 7.6qts) and immediately it started driving normally but my AT light is still on. I now notice that when I shift from Park to any other gear it shifts very roughly and and makes my car jerk. I called the Mazda dealership today and he said my transmission may need to be flushed which is what my dad also said days ago. If I take it to the dealership its gonna be $110 just to diagnose the problem, in which we believe the problem is a needed transmission flush. Has this happened to anyone? Can someone PLEASE shed some free light on me lol.