You get a ticket for speeding. You know you shouldn't be speeding but you did it anyway thinking you'd get away with. You get handed a fine for speeding that says you pay 100 dollars and you agree to pay that fine. Tomorrow a kid is injured by a speeding motorist, the community is up in arms and the town decides to raise the fine for speeding to 1000 dollar. You now have to pay the new fine. It doesn't make legal sense.
The penalty has been handed down and it was a YDT, but now with the current drivers and the testing of the new compound kevlar tires being tested for safety reasons, you're no longer running a YDT. You may have your own opinion as to why you feel Mercedes broke the rules and should be forced to pay the punishment, but that opinion does not have a legal foundation other than you think Mercedes got away lightly and should have paid a higher price.
If you can give me a legally justifiable argument as to why the speeder should now be forced to pay 1000 dollars versus the original 100 dollar fine, I'd love to hear it.
Retroactive law aka Ex post facto law which are unconstitutional in the US, but not, e.g., in the UK:
a law that retroactively changes the legal consequences (or status) of actions that were committed, or relationships that existed, before the enactment of the law. In criminal law, it may criminalize actions that were legal when committed; it may aggravate a crime by bringing it into a more severe category than it was in when it was committed; it may change the punishment prescribed for a crime, as by adding new penalties or extending sentences; or it may alter the rules of evidence in order to make conviction for a crime likelier than it would have been when the deed was committed. Conversely, a form of ex post facto law commonly called an amnesty law may decriminalize certain acts or alleviate possible punishments (for example by replacing the death sentence with lifelong imprisonment) retroactively. Such laws are also known by the Latin term in mitius.
I'm sure our resident legal expert ZA will have some input...