Why does engine and/or trans shut down after extended drive?

What is your question?

When I bought the car 4 years ago from a dealer in Falls Church, Va. (only 50000 miles); the car seamed in good running condition. I drove 150 miles home without a problem, but the very next day, running errands. the car shut down for no apparent reason (while I was driving) and wouldn't restart. It was towed to the local Dodge dealership repair shop where I was told that the computer diagnostic code showed an unknown problem with the transmission. The first thing they wanted to do was replace the trans. ($5500.00). When that wasn't an option, they replaced the shifter ($1000.00). On my trip home (70 MPH on I64), the car shut down again. This has occurred several times to the point that the car is no longer on the road with no answers. Other Dart owners have similar experiences. Recently, a former owner told me that the problem could be as simple as the wrong engine oil (non-synthetic). Could the repair be that simple, or am I looking in the wrong direction?

What makes this problem better or worse?

doesn't get better

How long has your 2013 Dodge Dart had this problem?

four years