| I had the same issue with my last car (Also a Dodge (08 Avenger))...My issue was caused by snow/ice build up in the wheel wells, behind the tires against the front of the rocker panel.
No symptoms when cruising below 100kph, but as soon as you kit 100, it stared the shakes...same thing you're describing...I pulled over, knocked out the snow/ice build up and the problem disappeared!
I'm assuming when you get up to that speed and the tires flare up (picture when they show a burnout occuring in slo-mo) the tires begin to scrape the snowy build up, causing grooves and causing the mean shake to occur...
Just my $.02 |