In Alaska, they appeared on his tail after a freaked-out local reported a UFO on the road. The police hung back, sizing up Mr. da Luz's silent little car, before blocking the road ahead of him with flashing lights.
It was the ninth time in three months he'd been pulled over.
Such encounters are to be expected when your daily drive looks like - depending on the view - an elongated flying saucer or a magnified cockroach.
"One woman near Vernon actually got scared and ran away at the sight of the car," says the Toronto-based Mr. da Luz from a Bellingham, Wash., brewpub.
Thankfully for Mr. da Luz, people usually let their guard down when they realize he intends to save the human race rather than vaporize it.
Last month, he set the Guinness World Record for distance travelled in a sun-powered car, more than 15,000 kilometres from Buffalo to Halifax to Inuvik to Victoria. Now he's embarking on a second leg, which could take him as far as Argentina if his finances hold up.
Most impressive about the record is that Mr. da Luz is neither a corporate-backed thrill-seeker like Virgin CEO Richard Branson, nor a greenpreneur, that growing class of environmentally focused, business-savvy entrepreneurs who hope to squeeze profits from their inventions and plans.
Rather he's just an Air Canada flight attendant with a dream, a hare-brained innocent in the high-minded world of solar transport.
Yet, he's rewriting the record book mile by mile.
"I don't have a final destination," he says in an accent that betrays his Brazilian roots.
"If you can mesh Forrest Gump and the 'If you build it' mantra of Field of Dreams together, that's me."
The road to the record started in 1987. A 19-year-old Mr. da Luz saw footage of the World Solar Challenge race in Australia and decided he would one day set the world record.
Then life got in the way.
"I kept putting myself down, telling myself that I didn't have the money or the engineering expertise," he says. "But eventually not following my dream became too painful."
In 1999, he officially launched the Power of One solar car project, knocking on the doors of more than 1,300 companies looking for financial support.
He didn't get a penny.
The tight-fisted rejection could have been a response to Mr. da Luz's business plan, or lack thereof.
"I haven't filed for any patents. I don't stand to make a penny. I just want to prove that the technology exists to save the planet today. I want to save the world, but I can't do it by myself."
No, to save the world he would need engineers.
"Marcelo came to me with a lot of ideas, but not a lot of expertise," said Ken Ellis, an engineering professor at Seneca College, where students and faculty volunteered countless hours of labour to the project. "It was such an interesting project I had to get involved. It goes to show that if you have a passion for something, anything, you will do well at it."
Mr. da Luz has mortgaged his house, blown $500,000 (his entire life savings) and called in every favour he could to get the project off the ground.
"I'm putting my old Honda Civic up for sale right now," he says. "It's the last thing I own."
He also broke up with a "wonderful, wonderful girlfriend" soon after embarking on the project in 1999.
"I haven't been so good at balancing the car with life."
But the payoff came in 2005, when it was ready for testing: a 3-foot-high, 15-foot-long fibreglass sliver capable of up to 120 kilometres an hour.
One problem: He couldn't get a permit to drive it in Ontario.
"So we test-drove it on the ice across Lake Simcoe," Mr. da Luz says. "I think it became the first solar car to operate at below-freezing temperatures."
He eventually registered the car in Barbados, acquiring the right to drive it virtually anywhere in the world under an arcane international law.
On June 12, 2008, Mr. da Luz set off from Buffalo for Halifax, and then back west for Victoria.
Averaging roughly 450 kilometres a day at 60 kilometres an hour, he took back roads to avoid hordes of motorists who would clump around him to snap photos.
Crowds appeared wherever he stopped.
"The whole town came out when he arrived," says Arvind Vashishta, an Inuvik resident who spent his lunch break ogling the car in July. "It looked like a flying saucer or an airplane. We don't see things like that around here. I was amazed he managed to get over the Dempster."
The 730-kilometre gravel Dempster Highway was, literally at least, the roughest patch of the trip.
"It felt like I was inside a washing machine," says Mr. da Luz, who's the first to admit that his car isn't the most practical means of transportation. A particularly steep hill or a couple of cloudy days can drain the batteries. When that happens, he pulls over, angles the topside solar panels at the sun and waits - anywhere from a few hours to a few days, depending on the weather.
Dozens of curious locals have put up Mr. da Luz and his two-man volunteer support crew. When they can't find a free couch they camp, an experience that's led to close calls with bears and wolves.
His celebrity has spread well beyond Canadian backwaters. His story of perseverance and environmentalism has attracted calls from journalists as far away as France, New Zealand and Russia.
"At a conference in Sweden a few weeks ago, people were stopping me on the street," he says.
Starting out, Mr. da Luz's sole hope was to set a record. But along the way he's lectured at numerous schools, fielded hundreds of questions and inspired thousands with his single-minded determination.
Mr. da Luz will drive until the money dries up. But what then?
"Make sure you write that I'm hoping to go back to work for Air Canada. Hopefully, they'll take pity and hold a job for me."