Buster,
I think the Mazda 6 has the same tranny as my 07 Fusion, which as I said takes the MC FNR-5 oil which I believe is the same as Mazda M_V oil. You will need to check, but your Mazda 3 may have the same tranny as my 07 Focus. If it does then you will be fine using the M1 ATF as it is Mercon V rated. I checked with Mobil tech recently and Fords FNR-5 ATF is not M1 rated.
I think the Mazda 6 has the same tranny as my 07 Fusion, which as I said takes the MC FNR-5 oil which I believe is the same as Mazda M_V oil. You will need to check, but your Mazda 3 may have the same tranny as my 07 Focus. If it does then you will be fine using the M1 ATF as it is Mercon V rated. I checked with Mobil tech recently and Fords FNR-5 ATF is not M1 rated.