Hi, So, our wonderful, efficient, sleek prius came to us used... well, more like drove hard and put up wet... and the Carfax indicates that in it's first 6 years of life it prowled the streets of Massachusetts. While I was rotating the tires at their 1 yr, 10k mark (look great so far!) I noticed that the brake drums in rear were not the only thing that was rusty... and the rear swing-arm shouldn't be quite so bubbly! I investigated first with my fingers, flaking off the thin paint shell left by the rust bubbles, then with a wire brush. The rust was concentrated around the welds on the rear swing arm, and pretty continuous, even around the main bushing attaching to the body. I investigated further and noticed rust bubbles on the entire swing arm and even rust starting to form on the torsion bar. I din't have naval jelly (was at my parents) to halt the rust, so after knocking down what was easily accessible from the wheel well I cleaned the area with a rag and then carb cleaner, then immediately hit it with some black rustoleum. Sorry, no pictures - again, at my parents and didn't have the camera. How worried should I be about this development? It's apparently been going on for some time. I think to really treat the rust properly I'd have to drop the entire rear suspension.