PORTLAND, Ore. -- Bringing vintage cars to the parks, estates, and golf course fairways where they can flaunt their beauty and compete for honors in the summer's many concours d'elegance events is a well-rehearsed process.
But as museums have assembled more exhibitions that showcase the artistry and historical significance of automobiles, the task of putting vehicles into public spaces -- often in the centers of busy cities -- has become infinitely more complex.
Cars, especially prewar classics, can be huge. And although museums are accustomed to dealing with large artworks, the vehicles present challenges on another scale.
"Our doors aren't as big as some of these cars," said Donald Urquhart, director of collections management for Oregon's Portland Art Museum.
Displaying cars as art took a step forward in 1951 with the Eight Automobiles exhibition at the Museum of Modern Art in New York City. More recently, cars from the collection of the clothing designer Ralph Lauren were displayed at the Museum of Fine Arts in Boston in 2005 and at the Louvre in Paris this spring.
The Allure of the Automobile opened at the High Museum of Art in Atlanta in 2010. With a few changes, the exhibition is in Portland this month.
It was not easy to persuade the owners to lend their cars to a museum at all -- let alone twice. When Brian Ferriso, executive director of the Portland Art Museum, approached the High Museum about taking the show across the country, he was told that getting the cars had been difficult.
But because Mr. Ferriso was approaching the exhibition as a study in industrial design, most of the lenders agreed to a second stint.
"I think they look at these objects as works of art rather than merely technological wonders," he said of the owners.
"Car museums contextualize the automobiles to the degree that they're very much in the pantheon of auto history. Now we're putting these in the history of 20th-century industrial design."
Mr. Urquhart created scale models of the three galleries that would house the cars for the summer and a digital fly-through for a sense of the space. Model cars and scale photos pasted to foam backing were placed in the architectural model to visualize the exhibition, arrange it thematically, and to make sure the cars would fit in the galleries.
Once the cars were in place, the museum had a new aspect of curatorship to consider: car maintenance. The batteries, gasoline, and oil must be tended to, and the museum had to be respectful of the city's fire code.
And there are the little things to remember, like which car has a small, slow leak in the tire that will need to be reinflated all summer. Some of the cars leak fluids when left to sit for months.
"When you rent a car, it comes with a photograph, and you mark the checks and the dents," Mr. Urquhart said. "These come with four-page condition reports and photographs and instructions on handling and instructions on maintenance.
"One lender will say, 'just knock the dust off with a towel,' and the other will send a box of towels with a page of instructions on exactly how to dust."
What makes Allure of the Automobile a treat is the opportunity to see such a wide variety of important cars in one place.