That just screams 'tire problem'.
This was my 6th documented visit to a dealer. On visit 5 they replaced all 4 tires with Michelin Defenders. Significant vibration still in the 70-90 mph range. Also shakes the wheel when coming off the highway. Not RPM or MDS related.
I documented the vibration coming off the highway (no brake application, just coasting). The vibration frequency is too high at highway speed to get picked up by the camera, but you can sure feel it.
I took a bunch of videos and this was the best one.