this game seems to grouping car into it's RACING CLASS, if you ever play rFactor or other PC Simulation Racing Games, you will understand it.
of course for people who used to play Console Simulation Racing (like Gran Turismo or Forza) it's litle bit confusing
IMO. Speed Dreams try to grouping it's car based on real Racing Series (just like majority of Simulation Racing Games) i think that's a safe bet. bexause if we try to do like Forza or Gran Turismo did. it will take a lot of energy, measure, and times. because 1 car can enter multiple class, categories, and series
for example is Corvette C6R. it could enter a GT and supercar categories. and it cam enter GTE, GT3, and GT-S seriea. it would be hard to code that thing
but indeed. same as you. i wish this game could. but it's shame that all i can do is just install and play