Please post the if the tires or something else fixes your pboblem. I've had the same symptom for a long time now (60-70mph). I've had the tires changed (worn out, not because of the vibration), then the new set was rotated, and I even had a set of snow tires. The problem has always been there. Never thought it would be a trans or engine mount. I just thought it's a half shaft or rotor something. But in the meantime I've had all 4 rotors replaced so that's not it. It runs fine otherwise, so I haven't spent money trying to chase it down. I'd be interested in knowing your result.
Andy
