Google said Monday that it has taken another big step forward in developing self-driving cars by building a fully functioning prototype of its own design.

“Today we’re unwrapping the best holiday gift we could’ve imagined: the first real build of our self-driving vehicle prototype,” Google said in a blog post.

Google unveiled its latest model – a tiny two-passenger car – in May, generating worldwide buzz. But on Monday, the company admitted that it was just a mock-up that lacked much of what you’d expect in a car.

“It didn’t even have real headlights!” Google said.

Google has said that its car would be built without a steering wheel, gas pedals and brakes, which are, in theory, unnecessary because passengers can just sit back and relax while technology handles the steering. To drive on public streets in California, however, Google must install traditional controls, just in case a human driver needs to take over.

Google GOOG plans to build about 100 prototype cars and test them for the next few years, the company said.

Previously, Google’s tests of the futuristic technology involved modified Toyota Priuses and Lexus SUVs. Over the past few years, the company had logged hundreds of thousands of miles in such cars on public roads.

Since showing off the mock up in May, Google has been hard at work on coming up with new prototype. The process involved using different versions to test individual car components that handle the steering and braking along with the computers and sensors required for autonomous driving technology.

“We’re going to be spending the holidays zipping around our test track, and we hope to see you on the streets of Northern California in the new year,” the company said.

As of last month, seven companies including Mercedes-Benz, Nissan and Tesla have received permits to test self-driving cars on public roads in California, making it a hotbed for the technology.