1998 Renault Megane car creaking & leaking liquid.

On the way home the other night, my car starting making a weird creaking noise whilst driving and quite a slow speed. When we got home, we checked around the car but the exhaust didn't appear to be loose and there didn't seem to be any other problems with the wheels etc. The day after, I noticed that there was some brownish liquid on the road under the offside back tyre(near the exhaust) which didn't seem to smell of anything. I moved the car up the street a few yards and the car creaked again and I noticed this morning that there was more liquid under the same tyre. Can anybody suggest what the problem might be? I am wary of driving it incase it is brake fluid which obviously could cause the brakes to fail therefore don't want to take it to the garage until I know what the problem could be.
Thanks