Just a few guides I came across a while back.Found some helpful stuff,a good help.
Some are not purely P/Cars but all are related.
Advanced Setup Matrix=ftp://www.jatekok.hu/hf1l/files/SetupMatrix.pdf
LMS 21 Step Setup Guide.Created for GTR2,but still/also applies to Project Cars.=https://steamcommunity.com/sharedfiles/filedetails/?id=443499370&insideModal=1