I have a 2008 MMH with 88,000 miles. Gas milage is still good, 28.5 avg. But in the last week, I have been getting a vary bad vibration, the whole car shakes at speeds of 20 - 40 mph
under acceleration. I have ruled out tire balance because it only does it under acceleration, and if I let up on the gas it instantly goes away. I am fortunate to do mostly highyway driving, so it has not made it in for a check-up yet. I do not notice the problem as much in ev mode, but it's tough to get the car under load at that speed without the gas engine kicking in, I am typically coasting or going down hill when in ev mode at this range of speed. Anyone experience this problem? I was thinking it could be a bad drive shaft to create this much vibration, or maybe it's time for new spark plugs and wires. Any help would be great, before I open the wallet.