rear struts
 

One side of my car is lower then the othere side and the lower side makes noise over bummps in the road.

The dealer said i need two new struts, mounts , and mybe one spring.

should I buy some used ones or new OEM struts, mounts and springs.

I would like to upgrade the rear struts but i can only find OEM struts.

I don't know what you can find for aftermarket these days, but I'd recommend against used struts. That's just me.

The road salt will help rust out the rear strut mounts. It just kind of sits on it if not washed away. Used mounts would be fine if not rusted, used spring too but doubt you need one. Used struts? I agree with Nick no way unless they looked brand new.