One problem related to engine shut off without warning has been reported for the 2005 Mazda MAZDA6. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Mazda MAZDA6 based on all problems reported for the 2005 MAZDA6.
I think the Mazda line of vehicles should be looked into. I have a 2005 Mazda 6 I sedan that from the very begining had issues. At 5000 miles I complained to the NHTSA because the car shut off on me on the highway. I took it to the dealership and the dealership could not duplicate the problem. The problem with the car shutting off has happened a few other times over the years and I've always had it investigated however the dealership could never find an issue. Finally it is 2011 and the car has 96000 miles on it and is completely shut down. As it turns out despite getting every piece of maintenance done on time and in order by the manufacturer cylinder #2 and #3 misfire and ultimately need "retrhreading?" . I wonder if this was a problem on the car to begin with. I have talked to a few other Mazda 6 owners who have had a similar experience as I did.