Move over, big-screen TVs, cell phones and tablets, because cars might steal the show at next week's International CES.

As preparations for the annual electronics show approach their climax here, two of the most awaited announcements aren't from big-name electronics companies but rather auto makers Toyota and Audi.

Each company plans to unveil prototype self-driving car technology here on Monday.

Toyota offered a tantalizing glimpse at its prototype through a 5-second video clip published online of its "Advanced Active Safety Research Vehicle."

The video shows a Lexus car decked out with various sensors on the front grill, rear wheels and the roof, the most striking of which is a spinning cylinder on the roof. A similar device is used in a self-driving car prototype developed by Google and in city mapping cars operated by companies including Nokia.

Lasers point at the cylinder and through reflections from the car manage to map out an accurate image of the car's surroundings complete with depth information that would be unavailable from a conventional camera.

The unveiling of the cars at CES is especially notable because the electronics show comes just a week before the North American International Auto Show in Detroit. That event is one of the largest and most important global automotive shows and is typically where the world's car makers make major announcements.

Several other car makers are also researching self-driving and autonomous automotive technology.

At last year's Ceatec exhibition in Japan, Nissan unveiled a prototype car that could park itself, while Volvo is working on a vehicle platoon system that allows cars to automatically follow one another on long stretches of highway. Alongside Google in Silicon Valley, Stanford University has developed a prototype self-driving car based on an Audi TTS.

Toyota is set to unveil prototype self-driving car technology at CES. The world's biggest car maker says it will show off its latest research, previewed in a short video clip.

Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is martyn_williams@idg.com