An investor in Tesla Motors Inc thinks it may be time for big competitors of the electric car maker to admit defeat on their electric models and focus on the next technological leap, perhaps flying cars.

While electric cars are a small percentage of overall sales, more automakers are making them, following General Motors Co's Chevrolet Volt plug-in hybrid and Nissan Motor Co's all-electric Leaf. Tesla started with a high-priced electric roadster that it is phasing out. It recently launched a more mainstream Model S sedan.

Tim Draper, founder of venture capital firm Draper Fisher Jurvetson, which backed Tesla when it began and is a shareholder, said the Model S launch and plans for other electric vehicles are bad news for Detroit's "Big 3" automakers.

Referring to the Model S starting price of $57,000, Draper said if he were a Detroit automaker, he would be looking to leapfrog Tesla. He spoke to Reuters on the sidelines of a technology conference in Detroit.

"I would be saying, ‘OK, they've won this. Now let's move to flying cars.'"

GM and Nissan officials declined to comment on Draper's statement, but a former GM executive called it "absurd."

"I'm not surprised that GM and Nissan declined to comment," said Bob Lutz, GM's former vice chairman and one of the people credited with helping to create the Volt. "It's so absurd that one doesn't want to dignify it with a rejoinder."

Draper, who bought the eighth Model S to roll off the production line, said he has no plans to sell the electric car maker's stock unless perhaps it becomes as valuable as Toyota Motor Corp's.

The Model S is Tesla's most crucial launch and it has said the vehicle will account for 90 percent of its revenue this year.

Tesla has said it expects to deliver 5,000 Model S sedans by year end and 20,000 in 2013, but three weeks it ago had built only 100.

Through August, GM and Nissan had sold about 13,500 Volts and about 4,230 Leafs, respectively, in the United States.

Tesla shares ended 1.7 percent higher at $28.28 on the Nasdaq on Wednesday.

This article is copyrighted by Reuters