California start-up Tesla Motors may have hit a nerve with its upcoming Model S electric luxury sedan. The manufacturer claims more than 500 people have signed up to pay $50,000 for the car in just one week, though there are still no firm dates to manufacture the vehicle.

TechCrunch reports, "Tesla says that 520 S Model all electric sedans have been reserved by customers in first week since it was announced. Each customer must pay a $5,000 reservation fee, which is refundable if they choose not to buy the car."

CNET explains, "The working prototype of the Model S was unveiled last week in Los Angeles." The all-electric four-seater "can go 0 mph to 60 mph in 5.6 seconds, has an electronically limited speed of 130 mph and can be recharged from any 120V, 208V, or 240V outlet. The car will be offered with a range of 160, 230, or 300 miles per charge, depending on which battery the buyer chooses, though Tesla has not yet said what the price difference will be for each package."

The delivery date for the car, however, remains uncertain. It's not even clear whether Tesla will find the money to build the car. Autoblog reports that Tesla is "attempting to secure a $350 million loan from the Department of Energy's Advanced Technology Vehicle Manufacturing Program for a plant in which to build the Model S."

CNET points out, however, that it's probably too early to count the little company out. "While the company has faced a mountain of start-up hardship, including a battle over trade secrets, a class action lawsuit, and a major leadership change, it has so far been able to deliver 320 of its Roadster models, its all-electric luxury sports car."

If you're in the market for a new car, check out the U.S. News rankings of this year's best cars as well as this month's best car deals.