Speed Racer (film)/Headscratchers

In The Movie, why the heck is Speed driving the Mach 6 in his first race? I thought it wasn't even built until after the M5 was totaled at Fuji. And then he's driving the M5 again at the Grand Prix... WTF?
- The Mach 6 is a specific type of racing car called a T-180. The Mach 4 is an earlier model of the same design and the Mach 5 isn't a racer at all, it's a production model car (and probably the last one Racer Motors made before switching to working on racers) that was modified for the punishment it would recieve in the Casa Cristo (Casa Cristo is a rally race, and rally cars are almost always production models). A possible reason why there is no T-180 called the Mach 5 is that they were simply forced to skip that one in the years where Racer Motors had no driver for that particular model. In one of the flashbacks it shows that after Rex died Pops pretty much abandoned his garage and there is a car visible under a dropcloth but we don't really get to see it. This is probably the T-180 version of the Mach 5 that was being built but never used due to Pops short retirement. By the time Speed started racing professionally there was a new version of the T-180 called the Mach 6 (because it was the sixth one built) that Speed used as his car before Thunderhead all the way through the Fiji race where it was destroyed and later re-built. Actually a better question would by why isn't the car Speed drives in the Grand Prix called the Mach 7 because it would be the seventh racer Pops built.
- The "Mach" numbers might not be a count of the cars themselves (Pops only built 6 racers in his career? Really?), but rather a version number. So Speed starts the film with a Mach 6, regresses to the Mach 5 for the Casa Cristo, and for the Grand Prix the family pulls an all-nighter to build another Mach 6. Presumably if Pops ever sits down and dreams up a new racer design, that'll be christened the Mach 7.
  - But the Mach 5 in the movie isn't a race car at all, it was Rex's personal car. Originally it didn't have the standard racing auto jacks or other features as they were all added for the Casa Cristo. Perhaps the "Mach" name is more of brand name used by Racer motors with the numbers representing the "generations" of the car. Therefore the Mach 5 (as see in the film) is the fifth production model car Pops designed, while the T-180 racing cars are the sixth generation of that design
It doesn't bug me (I loved every second of this movie, and watch it every time it's on HBO), but how big was the track of the Grand Prix? I mean, length wise? I want to know how many laps it would take to cover 500 miles.
- From what I saw, Speed hit "The Big Drop" twice, and the big drop seems to indicate that it's the only one, so I'd say Speed circled the track twice... so a highly-compressed 250 miles is my estimate.
- Yes, but by the end of the race there were no cars left on the track to stop him, so running the race any longer than the two laps shown would have been entirely pointless. Speed won basically because he was the last man standing rather than having the best time or the fastest speeds.
So after Rex Racer 'dies' the Racer family buried a body that they thought was Rex's but wasn't. So whose body did they bury? Whose body did Rex steal to pose as his own? Did Rex go corpse stealing or did he opt for a...fresher body?
- Speed mentions to Trixie that Rex's "body" was too badly burned to be easily recognized. Presumable Rex and fought and killed one of the people trying to frame him for the racing disasters and placed their body in his car shortly before he blew it up (this is almost exactly what happened in Racer X comic mini-series). Mom and Pops were too distraught to properly ID a corpse burned beyond recognition and instead decided it was him based on some personal effect the body had in its posesssion.
- Not to mention that when you're doing it with the cooperation of the authorities, its a lot easier. Police Coroner: 'Yes, we've entirely matched the dental records to your son Rex. I'm sorry.'
I seem to have missed it, but why is the Brandenburger Gate next to the finish line of the Rally? Does it take place in Germany?
- The rally takes place in a fictional nation called Casa Cristo (or something like that). It may simply be a copy of the Brandenburg Gate since some nations or groups in Real Life have been known to make replicas of certain famous structures
  - The route for the race makes no sense. They go from a desert to the Swiss Alps and the Matterhorn of all places without any real gap between. They do spend the night in between, but there aren't any deserts anywhere near Switzerland. Speed Racer Earth makes absolutely no sense.
  - It's not Switzerland or the Alps. It's a fictional country called Casa Cristo that's a geographical hodgepodge, just like many of the places in the anime. Of course it doesn't make sense.
Did anyone catch the specifics of Royalton's Hannibal Lecture at the point where he described exactly how the 43 prix was fixed? I don't really understand economics, but I'd like to know the details in Laymen's Terms.