Cooking for oneself is a great way to save resources and therefore spend less money.
Some folks set up on a tailgate or on little table at the rear of the vehicle under the open hatch, or with the rear door open and blocking view/wind. At parks stoves can be set in a bbq grill or on a concrete picnic table.
For folks looking to save more on food expenses, there are cheap but tasty approaches.
Scrambled eggs are notoriously difficult to get off pans. Some techniques:
Since carrying measuring cups and spoons can be unwieldy in a vehicle, 'dwellers may want to measure their ingredients by weight.