[tdpyron]

Like you - my 2012 BMW X5 3.5i lost an engine in a similar fashion. I had driven 160 miles and pulled in for a 5 minute rest stop. Upon leaving I merged into a line of traffic on the highway, then changed lanes and had to floor it due to mis judging the speed of the car coming up behind me. After full acceleration I found the car had shifted to neutral and no rpm. Luckily I could coast to the side of the road. Mechanic now tells me a locked cam shaft. (can't manually turn the crank, no oil in the coolant, no coolant in the oil). Had just replaced valve cover gasket and oil filter cover gasket and water control valves, days/weeks before the incident. Cause remains a mystery. Thoughts.