Yeah it certainly is. Ive experienced many vibrations over the years haha so feel your pain.
One thing I found though....i kept going back to the same garage to get wheels balanced etc, two or three times on my standard wheels 3 or 4 years ago now i think, due to an annoying vibration i had at 70.
Garage i used were adamant the wheels were balanced correctly, they showed me what they were doing etc and i had no reason after that to doubt them. I could see that they were weighted correctly in accordance with their machine....fine.
Roll forward 6 months after, and i had given up looking, (i was just goin to live with it for a year and try again in the summer months,) and my cousin got job at Aston Martin/ Jag in the Exeter marsh barton estate. I was up there giving the car a service with him one Saturday, and I asked if he could check he balancing just as the wheels were off, as a last ditch attempt. He ended up taking all the weights off, starting again, popped the wheels back on and since that point, i had no vibration atall! It had cured it.
All id done other than rebalancing was to change oils and fluids, whilst he re balanced the wheels on his machine. Marvellous!
It was only recently someone else had a similar issue... (Sylar something I believe) he had vibrations, etc but the garage saying they were all weighted properly, (on several occasions) yet like me, he took it elsewhere to try and they rebalanced and cured his vibes too.
Got to be worth a shot trying another garage and pleading ignorance, see what happens
you never know, you can either definitely rule out balancing, and get a second opinion..., or the problem goes.
