In developing our reflash for the MS3 I've found a few little interesting details. For those who like to drive it like their foot is a lead weight, the stock ECU records the number of times it has hit the rev limiter, it records the number of kms driven with the CEL on and it also records the maximum boost level held for more than 1s. It also records the total number of seconds the engine has been run WOT.
These can -as far as I understand be cleared by unplugging the battery for a minute or so, and I don't know if Mazda ever checks the values, but it certainly can tell them how hard you drove it if such a query were done.
-Michael