Open Inventory (I button). In the Miscellaneous section, find your car.
Right click on the machine and select Spawn vehicle. Park the car next to you. A car will appear next to you. Now it needs to be refueled.
In the same Inventory, select the Mined resources section, there find oil cans. Left click on them, and, holding the mouse button down, drag canisters onto the car, standing on the road.
Having completed this action, you will receive a message with a question, Do you really want to refuel your vehicle? Agree and your car will be refueled!
For, to sit in it, just 2 times left-click on it