Mazda3Club.com : The Original Mazda3 Forum - 2010 Mazda3 engine stalling and restarting while driving

I have a 2010 Mazda 3 with about 115k miles on it that has what I'm calling a mystery illness that I'm hoping someone here may have some insight. A few months ago, the radio would randomly restart itself while driving. Thought it was weird when it happened, then when it happened again, thought the battery might be going although it (battery) was only 3 years old. A month ago, I was stopped at a light and turned hard to get around a truck that was turning, and the car stalled and restarted itself and continued fine until I turned the wheel normally to pull over, when it did it again. Stalled, power steering off, everything, then quickly restarted. I was able to get to a safer area to completely shut the car off, sit for a few minutes, and started back up totally fine. Drove perfectly fine for 20 miles to my mechanic where they couldn't find anything wrong with it. It didn't stall for them when driving and there were no codes, so they changed the batteries since some connections were corroded, pro-rated the price, etc.

Two weeks later I'm driving down the highway when the radio restarts itself, so I get off the next exit and it stalls and restarts again when slowing down at a light. On my way to a parking lot, it stalls again when slowly driving, not during a turn. Get to the parking lot to shut the car off and sit like last time, but that didn't work - it stalled and started getting out of the parking lot and at the next light, the car just silently shut down. All dials went all the way up and all the way down, couple dash lights went on and then right off. Thankfully I was able to turn the car off, restart and pull over to a side street and got it towed to the mechanic where it's been for the last 2 weeks. No codes (but they did say the original new battery code was in there so it wasn't that something happened and it got erased), and it's still not happening for them when they drive it.

About 5 years ago, the computer face was replaced since the car did something similar going down the NJ Tpk (I can't remember exactly what happened and the mechanic is closed this weekend to look the exact issue/fix up). And about 3 years ago, the transmission was rebuilt when it completely frizted out when I was backing out of a parking spot and slammed on the brakes and quickly went into drive to pull back in since someone was screaming down the parking lot.

My mechanic is a decent set of human beings and don't want to start throwing parts at the car to fix it and run up a huge bill. Any thoughts or similar experiences and fixes are helpful!