Tcx82

Hi guys, i just purchased an 2008 with only 50k on Odometer for 14k. The car Interior and exterior was in excellent condition and it drive very smooth. But today I noticed a little bit of rusted on the left side and right side of rear wheels, near the brake lines /axels. I'm wonder is that serious? I check the frame there are no rust. I look at the car history look like it from Pennsylvania, so it worry me a bit.