How to check the coolant levels in an Audi A6?

I noticed that the coolant warning light keeps coming on in my Audi A6. How can I check the coolant levels to make sure it's not running low?

To check the coolant levels, start by locating the coolant reservoir tank under the hood of your Audi A6. It is usually a white or transparent plastic tank with a minimum and maximum marking on the side. Make sure the engine is cool before opening the reservoir cap. If the coolant level is below the minimum marking, add a 50/50 mix of distilled water and antifreeze until it reaches the maximum marking. Don't forget to also check for any leaks in the system. After adding coolant, run the engine for a few minutes and recheck the levels.