Hi everyone, I am trying to fix a vibration that comes up around 100 km/h on my 05 Cooper S Cabrio. I bought new tires and rims about 2 years ago and started noticing the vibration last year. Had the tires rotated and balanced this spring and was told 3 of the tires were out of balance so got that fixed but the vibration is still there (happened around 120 km/h before, now 100). Had the tires rebalanced at another garage and they found one tire was still slightly off so they took care of it but the vibration is still there. It's weird because the vibration level can change a lot from day to day. Sometimes you hardly feel it but most often it's really noticeable. On the odd day it's so bad you'll see the rear view mirror shake and you feel it in the whole car. I've been told this could be caused by flat spots on the tires (it's my second car and only driven in the summer). I would really like to get rid of this shaking as I love the car and plan to keep it for the foreseeable future but it's annoying not knowing what's causing it. I installed a couple of strut tower reinforcement plates this spring and plan to add a strut tower bar next year. Anyone out there have some suggestions?