slight vibration at and above 65 mph
2004 c5 corvette with automatic transmission. problem is a slight vibration at or above 65 mph. the vibration seems to pulse rather than being a steady vibration. it's there all the time doesn't go away. doesn't matter if the car is hot or cold. unable to pin down the location of this vibration but it feels like its coming from everywhere. wish I could be specific but it is a slight vibration. bought the car late last year (2nd owner). had this vibration when I bought it. since then have replaced wheels and tires, 4 wheel alignment, road force balancing, new shocks, taken car to chevrolet dealer who says everything looks fine nothing obviously wrong and the mechanic says the vibration (he noticed it to, just like myself) was normal and nothing could be done about it. his explanation which I really didn't understand involved something to do with the tires and frame having different frequencies and hertzs???? the vibration seems to be speed related and not rpm related.
I live in Minnesota, so if anyone can answer this question and knows a shop they can recommend that would also be really appreciated!