A brand new attraction experience is coming to Disney California Adventure, it has just been announced. The new attraction will be located in Cars Land, on the site of what is currently Luigi's Flying Tires - the current attraction will close permanently after February 16th, 2015.
As for what the ride system is, well that remains speculation at this point. What is rumored - and would make sense going off that concept art - would be a system similar to Aquatopia at Tokyo DisneySea:
This ride utilizes GPS guided vehicles (i.e. trackless) that move around independently from one another, in this case over the water. The Luigi ride could use the same technology to make the cars fly by one another, but of course never coming in contact. This technology is quite impressive and has already been used in three different attractions at the Disney parks in Japan.
Promising more details in the future, Disney has released what they can so far - read more from the park here.