This has to be done on the planet Oa. There's two vehicle spawns, you want the one on the right. Harley's Motorcycle is the last option on the second row.
There's two races directly in front of you. I did the one on the left, but completing any race will work. Additionally, if the driver is Green Loontern, obtained by completing all of his quests on the various hub planets, you'll get another achievement.