Q: My wife was driving this morning and heard a bang and thought she blew a tire or got rear ended. There was fluid that was leaking.

My wife was driving her car this morning and heard a bang and thought she blew a tire or was rear ended. She pulled over immediately and saw there was fluid leaking from under the driver side rear wheel well area. I was at work and came back to retrieve the vehicle. There was a trail of fluid stain I could see on the road but not a massive amount and it was not leaking anymore. I thought maybe it was a blown brake line, but I checked the reservoir and it was full. I checked the coolant levels and they were fine, and same thing with power steering. I drove it home and it still had plenty of firm resistance on the brake pedal and was not leaking fluid. I jacked the car up and took off the wheel but did not see any fluid stains or signs of a leak. The axel bushings on both rear wheels are looking pretty worse for wear, but I did not see any signs of fluid. I'm at a loss, but don't want to drive it to a shop in case anything happens.

My car has 210000 miles.
My car has an automatic transmission.