Where is the oil stick on a 2004 BMW 645ci?

On a 2004 BMW 645ci, the oil dipstick is located on the driver's side of the engine bay. It is typically found near the rear of the engine, close to the firewall. To access it, you may need to remove the plastic engine cover, which can be done by unscrewing or unclipping it. Always ensure the engine is off and cool before checking the oil level.