Sharpless went missing in the early morning hours of August 23 after she was out partying with her friend, Crystal Johns.
Relatives and friends say Sharpless got into an argument at a house party in Penn Valley, took off alone in her black Grand Prix, and vanished.
Sharpless' last contact with anyone was a text message to her 12-year- old daughter, that same morning.
Today, police say none of the vehicles recovered belong to Sharpless. Officials say they are mostly certain that Sharpless' car is not in the river.
Lower Merion Police say the boat ramp is a popular spot to leave stolen vehicles.