[realrundell]

Hmm, not to beat a point to death, but are you sure both front and rear brakes were dragging? The reason I ask is there, obviously, could be different root causes for your issue. As far as all four dragging; the first things that come to mind would be- contaminated fluid(should be ok if they were just flushed) or a misadjusted brake pedal pushrod. If it's just the rears, I would want to double check the rear caliper adjustment using the proper procedure per the workshop manual. If the rears are misadjusted or the park brake cable is misadjusted, the rears can drag and overheat to the point that they vibrate and can literally bring the car to a stop. I'm not saying that either of these are your problem, but worth a look.