In the EU version of the game the changes are:
+Added peugot 106(starter car).
+Added Vauxhall Corsa(starter car).
+Added Acura RSX(comes in stage 3).
-Removed Honda civic.
*Mazda miata mx-5 comes next to the SUV's(its a starter car in the US version).
This option lets you use both the US cars(civic and starter miata) and the EU cars(corsa,106) at the same time,for this feature you need to have model cars of all cars.