(CNN) -- Two Canadian women who said they were headed to Atlanta for a week of vacation and shopping were arrested after agents found 75,812 pills of the drug Ecstasy in the trunk of their vehicle at the border, U.S. Customs and Border Protection said Wednesday.

Officers at Detroit's Ambassador Bridge seized about 53 pounds (24 kilograms) of PCP-laced Ecstasy with a street value in excess of $100,000, authorities said in a statement.

The driver of the vehicle, which had a Canadian tag, told an officer at the crossing that the vehicle was hers, the agency said, but it was actually rented. A search began.

Officers found what appeared to be tampering with the rear quarter panel areas in the trunk, the agency said.

"Utilizing a fiber-optic scope the officers were able to observe what appeared to be plastic bags secreted inside one of the quarter panels," according to the statement. "Continuing their inspection they discovered more plastic bags hidden in the opposite quarter panel as well."

A field test determined the colored pills were Ecstasy, the agency said.

Shennelly Finn and Lashawna Morgan, both 24-year-old Canadian citizens, were arrested and turned over to U.S. Immigration and Customs Enforcement for further investigation and prosecution, authorities said.