I have a brand new car (NOT GM) and had vibration from first day. 3 times balancing in 2 different dealer ships could not help. I was told this GM dealership has high-end “Road force balancing” machine, so made an appointment. My technician Pat found all wheels are out of balance and 2 front wheels have high road force. For people are not familiar with that force, I need to say it is a force transfers to wheel/suspension from road, as a result of tire/wheel match mounting issue. He matched them and reached lower numbers. After road test, vibration was much better. My service consultant Marlinda was really helpful. If you have any kind of vibration which regular balancing machines are not able to fix that, perhaps you have too much road force on wheels. Definitely I do recommend this place. Appreciate for that amazing service.