I’m not sure Hal should really have an earth vehicle, he can literally fly everywhere. So if he does have a vehicle I would think it would be a show off vehicle like a muscle car or a motorcycle, just something he doesn’t need but that he puts whatever money he may have into just so that it can look cool.
If not that, he needs his own private spaceship. Just some random alien ship he saw out in space he thought looked cool and his pilot instincts couldn’t resist, occasionally he has either Barry (Flash) or Victor(Cyborg) to help supe it up.