I buy two of every car if:
-They are road cars;
-They are race cars that have two liverys in-game;
-They are race cars that have permanent tune changes;
-There's an engine swap for said car.
Basically, I want to have one of EVERY Road car, at the very least, to have one stock and one fully tuned with widebody. And then if there's cars that have engine swaps, I'll buy even 3 or 4 of that car to have those engine swaped (also fully tuned later) cars.
If the Race Car is available in the game with two different liveries, like for example some GT3 cars, the 2016 LMP1 cars and the Toyota GR010 which have two liveries with different numbers, I also buy those.
I however don't buy duplicates of race cars if they don't have an extra livery, as most of the race cars can be tuned without having permanent changes.
However, some Race Cars that have permanent tune changes that can't be undone, like the Ferrari 250 GTO or other older race cars, I'll buy duplicates of them as well.
Even the Chaparral 2J or Porsche 917K which only have one permanent change (Body Rigidity) I'll buy two of those as well.
Cars like say, the Peugeot 908 HDi FAP, have no permanent tune changes and only have one livery so I'll buy just one of those.
All of this requires a crapton of credits though. I have about 80% of the cars fully tuned and have duplicates of every single one of them aside from the Alfa Romeo Giulia TZ2 which hasn't been in the LCD for about 3 months now...
