As I understand it, the car simply won't run with engine tweaks or third-party wheels and tires. The first is understandable, because it may damage the engine. The second is not understandable, and looks like monopolizing the upgrades/replacements market. That is illegal -- the same has been attempted by Lexmark (inkjet cartridges) and by Nokia (batteries for mobile phones) iirc.
The speed limit probably only applies when the GPS says when you are on a track. In itself that's sensible, because you may be only driving near the track (to watch the race); GPS is not that precise. But it does create a loophole: you can thrash the car quite badly but stay below 180 km/h. Even worse, an owner who doesn't want to pay the $1000 is tempted to go for a blast on a public road. (Street race, anyone?)
If Nissan is really concerned about warranty claims, they should let the car log abusive driving, like excessive G forces and high revs. They could even put a warning on the driver's display if he is driving wildly ("Easy, son. Three more minutes like this and your warranty is void.")