The next time you plan to hit the road in a rental car you might want to bring along some antibacterial wet wipes. 

This month, NBC’s TODAY show concluded its summer series “The Dirty Truth,” with a segment revealing the hidden germs in rental vehicles. What national investigative correspondent, Jeff Rossen, and his hired team of scientists found is enough to make a person think twice before getting behind the wheel.

Besides pointing to obvious stains, the scientists swabbed the steering wheels, gearshifts, door handles, and GPS units of six vehicles from top rental companies in Orlando, Florida. Out of the 25 collected samples, 22 tested positive for germs. 

While most of the GPS units were clean, door handles and steering wheels were “teeming” with bacteria, the report said. In fact, on a steering wheel in a minivan the scientists found dangerous levels of human bacteroides — also known as fecal matter.

“This is a serious public health problem; it’s a real wake-up call to America,” Robert Glatter, an emergency room physician at New York City’s Lenox Hill Hospital, told the show. “We’re talking about diarrhea, vomiting, leading to dehydration — leading to very, very bad situations.”

Though two of the six vehicles passed the “clean test,” Rossen warns that determining how clean a car is goes well beyond seeing visible soils. 

To help keep potentially harmful germs at bay, use antibacterial cloths to wipe down surfaces within a car, and wash your hands immediately following a trip.

To see TODAY's report in its entirety, click here.