“Speedy decision-making is part of a start-up’s DNA,” Mr. Toyoda said in a joint press conference with Mr. Musk in Tokyo last week to discuss the partnership. “That’s what we want to absorb.”  He added: “Remember, Toyota was once a start-up, too.”  As executives, Mr. Toyoda and Mr. Musk could not be further apart. One is the staid scion of Toyota’s founding family, groomed for the top job for years, a shy character who seems more comfortable mixing with the Toyota ranks in a neatly pressed factory jacket than appearing in the media spotlight. The other is a South African immigrant-entrepreneur, a co-founder of PayPal who last year showed off Tesla’s upcoming Model S sedan in leather boots and designer jacket. In September, Mr. Musk wed actress Talulah Riley in a lavish ceremony splashed across the pages of celebrity Web sites.  But more than a difference in cultures, the two companies share divergent views of the future trajectory of electric automobiles. Mr. Musk is a firm believer in a decisive swing toward electric cars, and would like to enter a wider market in 2012 with a cheaper electric car.  “In the long term, all vehicles will become electric,” he said last week in Tokyo. “It’s a question of when, not if, and we hope the transition will come sooner, not later.”  Mr. Toyoda and his colleagues are more cautious, with Toyota executives often talking down the all-electric car in favor of the company’s gas-electric hybrid technology. The company has invested millions of dollars in its Prius gas-electric hybrid and is not eager for a quick switch to electricity, analysts say. Toyota has said it will introduce hybrid versions of all of its models by 2020.  And yet, as momentum builds around all-electric power trains, Toyota has been increasingly criticized for lagging behind in next-generation automotive technology. Nissan Motor plans next month to start selling the Leaf, which it calls the world’s first mass-produced all-electric car. General Motors will soon introduce its Chevrolet Volt plug-in hybrid.  Toyota is also set to introduce its own all-electric vehicle in 2012, a car based on its iQ ultra-mini compact that the automaker is developing independently. But Toyota has signaled that it considers the iQ a niche car, one mainly tailored for short-distance commuters in Japan.  Toyota is also leasing limited numbers of its new Prius plug-in hybrid to fleet customers, and is planning a wider commercial rollout in 2012. Compared with the original Prius models, the new one plugs into an electric socket and operates only on batteries at higher speeds and longer distances.  Mr. Toyoda said the market had simply not yet chosen the best low-emissions technology, which was why Toyota was preparing for all options. “When customers do give us their answer,” he said, “I want the company to be ready.”  Still, analysts say the electric version of the RAV4 — a mainstay in Toyota’s S.U.V. lineup — could signal more openness by Toyota to the idea of electric power trains for more mainstream models.  In planning a RAV4 electric vehicle with Tesla, moreover, Mr. Toyoda has displayed his own signs of being star-struck. The chief executive warmed to the idea, officials say, when he was shown a letter written by Tom Hanks to The New Yorker, in which the actor talked enthusiastically about a previous electric version of the RAV4 that he bought in 2003.  That would have been one of the 1,500 or so all-electric RAV4s that Toyota leased from 1997 to 2003 in response to stringent but short-lived emissions regulations passed in California. “The letter made an impression on him,” said Masami Doi, a Toyota spokesman. “It convinced him that Americans thought the idea of an electric RAV4 was cool.”  Toyota’s deal with Tesla has been a bright spot in an otherwise grim year for the Japanese automaker. Over the last 12 months Toyota recalled some 11 million vehicles for faulty gas pedals, floor mats that could trap accelerators, and braking and engine defects — each recall tarnishing the company’s once-sterling reputation for quality. As a result, Toyota’s United States sales have fallen off, despite generous incentives.  The company’s $4.46 billion profit for the first nine months of 2010 trails Ford’s earnings of $6.37 billion and General Motors’ earnings of $4.77 billion during the same period, according to figures compiled by Bloomberg.  Tesla, meanwhile, is seeking to build credibility among investors as it struggles to become profitable.  Despite the attention it has brought, the company has sold only about 1,200 of its electric sports cars, and has never turned a quarterly profit since its founding in 2003. According to a May filing with the Securities and Exchange Commission, since its inception, Tesla had incurred cumulative losses of $290 million through March.  But the Toyota partnership is helping Tesla attract new investors. Earlier this month, Panasonic, the Japanese electronics company and the supplier of Tesla’s batteries, said it would invest $30 million in the start-up, acquiring an approximately 2 percent stake.  Tesla’s share price has soared since its public offering on June 28, rising 80 percent and reaching a new high of $30.80 on Monday.  For now, Mr. Toyoda and Mr. Musk are at pains to demonstrate a mutual adoration. On his trip to Tokyo last week, Mr. Musk presented Mr. Toyoda with a Tesla Roadster painted wine red in a tribute to their meeting in California. Calling Toyota’s manufacturing technology “the best in the world,” Mr. Musk said Tesla had “a lot to learn” from the Japanese automaker.  Mr. Toyoda was also uncharacteristically expressive, vividly recalling his first ride in Tesla’s Roadster in May. “I could hear the wind as we drove,” he beamed. “I felt like I was on a yacht in the ocean.”  A version of this article appears in print on November 17, 2010, on Page B5 of the New York edition with the headline: An Unlikely Alliance Quickly Results in an All-Electric RAV4. Order Reprints| Today's Paper|Subscribe
The prototype, developed by Toyota and Tesla Motors at remarkable speed, indicates that each company is learning from the other.