Squeaking noise from rear of car?

You need to check the rear suspension of the car. It sounds like the springs or shocks are out of alignment, missing or damaged. If you are not mechanically inclined, take the car to a garage. A full inspection of your vehicle to tell you everything that is wrong with the car should be between 30 to 70 dollars. Many of the reported items can be fixed easily by buying parts at Kragens. Also, you find out if there is anything major wrong that needs attention.