Is rear spring breakage common on this car? I was told it was by a garage.

There are no leaf springs - they're all coil springs. I believe it is common because the same thing happened to both my rear springs then my front spring (at around 195k miles). I changed them out for new ones and got new shocks and struts at the same time - now the car drives like it just came off the showroom floor! BTW - you can save money by changing the shocks and struts yourself, but leave the springs to the experts - they're very dangerous to change if you don't know what you're doing. Good luck!