Choose the first intersection on Windrush and pick the default car. If you have the elite skin for beating the game, this will be even easier. The four cars are each in one of the corner of the map. Start to pile up the cars and wait for the God Cops to appear. Now quickly move from one Sport Car to another and use other cars or a direct hit with the crashbreaker to damage them. When they start burning, go for the next one.
After the first two cars, pile up the traffic again and wait for the magnet power up. Now go for one or even the bot cars. If you still have one car left, wait until there are only 5-8 vehicles left and make your move. At this point you shouldn't really fail the event and can concentrate on the last car.