The vehicle was taken into dealer for a factory recall to replace the rear driveshaft assembly. the car was driving completely normally when taken in for this service. but when picked up, the car was unsafe. it drove normally at low speeds leaving the dealership. but a couple of miles later when getting onto the freeway, at about 50 mph, the rear end started to feel like it was a drag on forward movement, and felt like it was swaying from side to side, making the vehicle very difficult to control. no unusual noises were heard. emergency flashers were activated and speed reduced to 25 mph to try to maintain control of the vehicle. the first off ramp was taken, and the dealer notified. the car was towed back to the dealer, who kept it for the next 36 hours. the dealer reported no problem could be found, and no repair had been done. the vehicle has driven completely normally again since then. *tr