Tesla buyers wait in lines hundreds deep to place $1,000 reservations on a Model 3

Early adopters of Tesla Motor's new electric car, the Model 3, lined up outside showrooms around the world on Thursday to put down money on a vehicle that none of them have yet seen. Some fans even camped overnight to first in line for the privilege of paying a $1,000 deposit for a car that will have its public debut at an event on Thursday evening. The first deliveries may not come for another 18 months.

In response to the outpouring of interest-and money-Tesla Chief Executive Elon Musk promised a surprise to those who waited in line...