Actually it's my wife's car. 2009 Saturn Aura with under 20K miles. Problem happened 3 times in the last year. Dealer services since new. They have no clue.

Here goes and I am including two problems as I think they are related. Driving normally in traffic, Normal speeds. The power locks (all four), start to lock and unlock by themselves. In about a few seconds the car will loose power, not accept gas but keeps running. In a few more seconds (10 - 20) as you struggle to avoid getting hit, the car will rev high rpms and then lurch forward. It will drive normally for a few seconds and then repeat the above process. First time dealer had for 5 days. Nothing. 2nd time they drove it on lot and experienced the issues. 3 days ago till now, they are finding nothing. It was in for a recall for the connection of the BCM in the fall of 2014. My wife was narrowly missed in a busy intersection when it last happened. She is terrified to drive the car, even though she loves it. It has turned into a love / hate relationship.

I doubt that GM does not know what the problem is after reading hundreds of threads online looking for this solution. And what the hell is an "immobilizer system"?