Hiya Clarky,
I'm new to the game. I'm a Subaru racing guy (hell, I've only replaced 2 racing engine this year) in RL and I have spent a majority of my time in the game in a Subaru. I plan on working on learning the tracks and game physics in the Subies. Slowly getting a hang of the game but I am winning races online in the GR3 and GR 4 WRX/STi but I've raced less than 10 times online.
Right now that only thing that I change on the GR4 is camber (as the cars are notoriously camber deficient). The GR3 Subaru is fantastic right out of the box and I never feel lacking in it against low-level competition. I am DR D and SR A.