Hi Justin, I welcome you to the forum, and I tell you that I have moved the topic to "mechanical problems" for being the most successful place for your consultation.
The problem you mention about your Hyunday Elantra can be as simple as it has a broken return tube,
so that when it is stopped it does not stain fuel to the ground, or at most it will throw a few droplets but when you start it, the car is throwing the fuel as the engine pumps it again to the tank.
Another cause that can be is that some tube of the wallet is broken, that would be seen because when filling the tank to the mouth, it would throw some fuel to the ground.
A less probable cause (because the fault witness would turn on) is that the canister's electrovalve valve is open, the canister is an active carbon filter that absorbs the tank gasoline vapors and sends them to the engine to avoid polluting emissions, the problem is that if it remains open, the engine continuously aspires the vapors, the vapors are increasing the consumption of fuel.
The first possible causes (broken pipes or lazy clamps) are quickly getting under the car with the engine running. The third cause, that of the canister, has to do with you a workshop.
Greetings and take advantage if you are still under guarantee.