When I'm driving about 55-60 mph at 2500 rpms the car begins to shake (almost as much as it does when it wants to stall) When I slow down it stops and when I go faster it stops, it just started happening almost a week ago. Any ideas? Already have an aluminum DS could it possibly be a tire out of balance?

 

It could be that your tires are out of alignment, although I'm not quite sure why it would stop. But also, I dont think aluminum driveshafts always solve the problem, It still has to be balanced.

 

Car was just aligned about a week ago.