This Thread should have what you need. They're all hard at work determining what gives you the most credits per hour, and they adapt with every update.
ThanksJust do circuit experience to get a car you want and then do online races.
Finish the singleplayer first before buying a car yourself. Since you get random cars by the time you finish SP you will have about 60 cars given to you for free. So dont waste cash on something you might get for free...then you just spent money you cant grt back
Also by playing SP you will be getting tons of cash and xp anyway. Obviously afterwards the money glitch is great because Sport races dont give as much or as frequent cash n XP.
As stated earlier the game gives a lot of free cars, you get one every day just for logging on and driving a few miles. I have not found a need to "farm" for cash or xp and have bought everything I have wanted to buy so far.
I do play a lot though both on line races and offline learning tracks and the cars I like behaviors and limits with my skill set. I usually only buy cars that I know I really want or the car that may be needed for a particular race I want to use it in. Other than that the prize and gift cars are overfilling my garage with most so far not used at all.