I had an old car whose engine would die if it didn't get gas, so you would always be giving it a bit of gas at all times. When you came to a stop, you had to push slightly down on the gas and all the way down on the brake, otherwise the engine would shut off.
Also would allow you to take the key out of the ignition while the car was running and it would keep running so you could unlock house doors with your keys. My parents actually sent it into the shop to "fix" that. I still don't know why they spent money to get rid of a feature. Were they afraid I would leave it on without the keys? The engine would just die without someone to push down on the gas petal.
I had a car that needed gas, and was a stick shift. I called the technique three footing. Basically I jammed my heel on the brake and raked my toes on the gas pedal to keep the engine running at a light or stop sign.