One happened in Bryn Mawr. The other, more recent, happened Tuesday at SEPTA's Villanova train station in Radnor.
In the second case, Radnor police are looking for a 2009 black Porsche Cayenne as well as a man in a brown hoodie who took it from its driver Tuesday night.
"A black male approached the vehicle and used some kind of language ordering her out of the vehicle," said Radnor Police Lieutenant Christopher Flanigan.
It happened at 7:50 p.m. Tuesday.
The SUV's driver was parked along a curb waiting for her husband to arrive when the suspect got in the passenger side.
One of several witnesses tried to stop the carjacker, who moved quickly.
"He is able to open the door, forces her out of the vehicle," said Flanigan. "She exits the vehicle. He rapidly jumps over the console and takes off as a witness attempted to get him to stop."
Police say the stolen vehicle has a North Carolina tag, OBX-53054.
Coincidentally a black 2008 Cayenne was parked in the same location Thursday.
Its owner, Debbie Boyle, runs a nearby coffee café. She just learned of Tuesday's carjacking and admitted she rarely thinks about her safety at this busy station.
"There is always so much traffic and student commuters who come in here," said Boyle. "I'm never concerned. That's why it is a little upsetting."
Four nights earlier and two miles from the train station, at the Beaumont retirement community in Bryn Mawr, a thin man wearing a hoodie used a gun to take a 2007 Mercedes from a resident.
Authorities say at this point there is no known connection between the two crimes.