I've been looking into getting my ATF changed. 2015 Mazda 3, 52000 mi, just purchased used. Instinctively I'm afraid of a flush, but a drain and fill isn't cheap if I don't do it myself. There's two Mazda dealers near me. One has given me several different answers but basically they can only drain and fill. They other had assured me they can flush it with a non pressurized method via a device they got about a year ago just for automatic skyactiv transmissions.

My question is, does this sound like BS, or does it sounds legit? Is there really a Mazda dealer transmission flush that doesn't actually use pressure to flush the system and rather is just hooked up while the car is running?