Halon helped with the Car Fu previs through a lot of trial and error. They tried to make abstract concepts feasible and had a lot of creative freedom.

After designing tracks, Lee tested the action and shot action pieces with cars they modeled and rendered in Maya and then cut them together. Then they did more refinement and look development. "We looked at a lot of photo reference that was very sharp and contrasty with no depth of field, and a lot of anime references. We tried to figure out how far to push reality. Some of the ideas were incorporated into the script.

Another area of exploration was the Car Fu choreography. "We did a lot of trial and error concepts, some worked, some didn't, some were funny," Lee continues. "In the beginning, we debated whether or not the cars would have the same jump jacks from the series or maybe the car wheels would pop out like limbs. We were trying to make abstract concepts feasible or how to make it feasible. In the end, it was very rewarding because we had a lot of creative freedom."

Lee also came up the idea of the conveyor belt as a design tool that eventually took on greater significance. "When I was doing a piece of the teaser, I figured that it would be faster to animate cars on a conveyor belt with a bend deformer. When it expanded, it looked like a crescent moon, which is what John Gaeta called it." They discovered later on in pre-production that it was not only convenient for the animators to work on this conveyor belt but also stylistically it reminded them of anime with the cylinders of track sliding to indicate movement without actually having to draw three-dimensionally.

Lee was also instrumental in using QuickTime vr of scenic locations as a tool, which later formed the basis of the spherical bubbles. They called this HD QTVR. "We found these websites that provide full screen QuickTime vr of various locations around the world. And because I had this 24" monitor it was quite stunning to view these sites, so I bought this program that allows you to convert these QuickTime vrs into images that I can reapply in Maya to make my own vr spheres. Initially, I suggested that this could be a quick way to previs a scene in this location. And John obviously saw beyond that and realized that this could be a stylistic tool. What if we form multiple bubbles? At first, I couldn't understand it. So he was talking about onion layering multiple bubbles [providing] this pseudo parallax when you move around. Also, connecting this spherical vr together and having almost like steady cam moves along the bubbles. There were a couple of tests and I was surprised at how well it worked. The concept involved spinning the bubbles around people talking and wiping the screen." One instance occurred when Speed tells Royalton that he can't race for him and Royalton screams that he'll never race again. However, the filmmakers took the concept further by transitioning to a scene of Speed racing.

Digital Domain's Patrick Perez (Stealth), an animator and previs artist, worked out of the Venice-based studio, where the previs pipeline was set up. This pipe consisted of directly exportable rigs, animation and camera paths straight into their post pipelines. "I consider this a critical strategy in so far as the turn-around time from director approval to processing finals was halved, if not better due to the common pipeline," Gaeta concedes.

Perez focused on DD's portion: the Thunderhead and Grand Prix races. "It's funny, but before we took this on, we were thinking this could be a recipe for some craziness. But all in all, it flowed fairly well. The pipeline was pretty solid and we had [good] rigs to work with. We had our track system down, so really it was just a matter of art directing the shots. There was definitely a lot of trial and error to come up with something different, somewhere between anime and a real world situation, especially in the early days before they took off for Berlin. I was working with the Wachowskis in the office in Burbank and so there was a lot of exploring of ideas. It was actually a very cool time because they were open to input from animators and would look at what we'd do as a proof of concept test. That three-month period helped nail down how things should be moving, which, of course, was then refined during the rest of the show. Fundamentally, most of the motion aspect of what I was dealing with was fairly well hashed out.

"The central hub was in Berlin to make sure everything followed certain standards. In this situation, I was actually putting sequences together, so I would do mini-edits, different ideas for pieces of action, and would send it to them to provide context for what was happening. For instance, during the climactic Grand Prix race, there are these slalom maneuvers through half-pipes and Speed goes up on the wall and does a jump jack off some spikes. Then Larry [Wachowski] came up with the idea of Speed flipping and hitting the front of another car, which flips and gets caught on one of the spikes and then explodes. Through experimentation, one idea led to a series of progressions."