There's no door-to-door action in the World Time Attack Challenge, there's no paint swapping at all. The aim here is to get around the track as quickly as possible -- there's only one winner as a result.
Competitors fly in from all over the world to try their hand at the challenge and be crowned the fastest on the planet.
To get your car on the circuit there are a few pretty big hoops to jump through. First you have to build your car to Australian spec to ensure it passes scrutineering in Oz, then to have to make sure it actually gets there. If, say, you're based in the UK and want to enter you need to get your car to the track. Now, if your car is road legal (unlikely) you could drive it to the land Down Under but as it's a racing car, you'd probably end up deaf and broken before you've left Dover. No, you'll probably have to send it to the competition in a container on a boat.
Now, this is fraught with danger because there's a chance that (1) the boat'll sink and (2) the container may end up in a different country altogether. However, if all goes well, you're sorted and able to race.
The cars that run in the WTAC are all tuned to perfection. They're lightweight, fast, and at their peak. Spoilers, wings, and vents adorn the racers' cars where once there weren't any aero tweaks; similarly turbos have grown, exhausts have expanded, and interiors have become more sparse.
WTAC is the pinnacle of precision motorsport, and it's only going to get bigger and bigger.