You're not imagining things if you've recently spotted an oddly shaped car topped with solar panels in California.

It was probably Stella — a family-sized solar car — which finished up its U.S. debut trip on Sept. 24. It's believed to be the first solar car that can comfortably transport four people — more than any other solar car, according to Tom Selten, manager of the team from the Netherlands that designed the car.

"A four-seated car is (in our opinion) functional and essential for families," Selten wrote in an email.

The car is designed for traditional roads and can operate on a single electric charge for up to 500 miles. Its inaugural road trip was in Australia, the battleground where solar cars duke it out in the World Solar Challenge. Stella won the "Cruiser Class" contest for practical cars, among other accolades, last year.

It might be a tight squeeze for an average person to fit inside, however, because the car's only about 4 feet tall, as Auto World News pointed out.

But Stella is yet another glimpse at how sun energy may change the way we travel. Using solar energy to power cars is already on the minds of automobile manufacturers. Ford, for example, has a car in the works that can last about 21 miles on sunlight alone.

"We think it is necessary to show the world a fuel-free future by making practical solar cars," Selten said.

The car completed a road trip last week along Highway 1 from Los Angeles to San Francisco (about 385 miles), the most traffic-heavy and hilly environment the car has traversed. Stella arrived in Detroit in early September before truck drivers transported it west.

Stella is now heading home back to the Netherlands.