shuts off while going down road and after pulling off road and 1 to 3 tries it starts and goes days or weeks before doing it again.
If CEL is on, get codes read and post back.
If no CEL, possibly crankshaft position sensor.
Ask your shop to narrow down the problem to either “no spark” or “fuel system problem”. Coincidentally a similar problem was discussed on a recent Car Talk podcast. 1990’s Subaru as I recall. It would s top running at stoplights, then would crank ok, but not restart. It would often have to sit unused overnight before it would start again. Caller’s husband tested for spark, found none. Ray thought it was probably a faulty distributor sensor. OP’s car probably doesn’t use that particular sensor, but a failing crank position sensor would cause the same symptom.