open up ur festivals mainly Byron bay to level 5 so u can race goliath run as many laps as u want the more u run the more payout use horizon edition cars particularly credit boost cars and u will earn plenty I normally do a minimum of 4 laps when I do goliath and I make sure I run it in something comfortable, u can blueprint ur own race and set what cars u want to race or race against I normally do a pro touring run or a pony shootout etc... it's all in grinding for the buck.