I own a 2014 Jetta TDI. I have been very satisfied with this car until about a year ago. On backing out of a parking space, the car started to jerk and lost power to the extent I thought it was going to stall. As fast as the problem started it corrected itself and had no further issues for a couple of months. The same thing happened again so I took it to the dealer. $100. later I was no further ahead. The Service Manager said the car was scanned and showed no faults. Was told a tech spent about an hour on the problem driving the car at various speeds both on their lot as well as on the highway but could not find any issues. A friend suggested I add Stanadyne to the fuel which I did. The the car definitely performed better with no sign of the jerking/hesitation. After using the additive for a few months I stopped as I was curious what would happen. After a few months I noticed a slight hesitation from time to time but nothing as dramatic as before. I had the car scanned once again but still is not showing any faults. Any suggestions?