[teddyca]

You could be correct. I have EVERYTHING BMR in the rear, but by trying KingLT1's suggestion I can put it in neutral, cost, and it goes away. None the less if I get a free flush it is a win win and I possibly eliminated 1 thing.

Originally Posted by Hyprblu

More than likely rear wheel balance issues. My M6 does the same thing 52-65 under acceleration. Admittedly I'm missing a few weights from the rears. Stiff tires and the suspension tight transfers vibration into the body.

[teddyca]

Update up top. I hope this helps someone.