NHTSA Complaint #11488751 — 2017 BUICK VERANO

Vehicle seems to loose power, radio & power sterring turn off and back on constantly. Shows message " Service Stability Track". I took it back to the lot where I purchased it, they had 2 different mechanics look at it and they could not figure out what is wrong with it. Picked up the vehicle a week in a half later and the vehicle was fine for a week or so and then it started up again. all power is lost on the vehicle while driving, backing up or parking at times, then it turns back on, on its own. Its like it losses power for a few seconds, steering wheel gets hard and radio turns off. Then it turns back on. Its gotten to the point to where its done it on sharp turns. This not only puts me at risk but other people. No service engine light one, gives either "service stability track" or " service power steering" or " collision sensor maintenance", but not service lights are on, no codes.