My 80 yo Dad has a 2014 Charger V6, 8 speed automatic with about 80k miles, and he’s been the only owner, meticulous about routine service being done. In the past few days, his car has developed a noticeable shudder while driving, usually between 10-40 mph. The whole car seems to shudder, like it is slipping out of gear for a second then it grabs and surges forward again. This is occurring mostly in level ground, both accelerating and at stable speed. Once when I was with him today, it did this 4 times in 20 minutes, and I glanced at the tachometer during the episode and it seemed to have jumped during or at the end of the shudder. He tells me that the car stalled twice today in association with two of the episodes, once in a parking lot and once after sitting in traffic and pulling out on a grade. In the past, riding with him, I’ve noticed that while at a stop on a moderate hill, with the car in drive, the car will drift backwards a foot or so if he takes his foot off the brake, enough that when he realizes it, he’ll stomp on the brake and we’ll both get a little head jerk. I don’t know if these are related problems but thought I’d put it to the forum to see what you think. The drifting back has been happening 2-3 years, while the shuddering/stalling is only 1-2 days. Thanks in advance for any comments before he takes it to his mechanic.