Where would I pour head gasket leak seal in 2000 Ford Taurus?

Looking to seal up in leaks and planned on pouring the fluid into the coolant resevoir.

Take the radiator cap off. Start the car, if the fluid goes down add that stuff right there. If the fluid don't go down drain some out, then add it. Don't put it in the resevoir tank. Your car might never get.

You pour it on the ground, along with the money in your wallet. Sorry, but there's no "Fix It In A Can" or "Repair In A Bottle". Save your money and do it right. How do you know its a headgasket? Leak down test? What fluids appear to be missing?

Are you reselling the car? Then put directly in radiator. Even if you must remove top hose and pour down that way. I know some cars no longer have radiator caps.

Keeping car? DON'T do it. This band aid is good just long enough to make you wish you'd never done it. Properly replace head gasket and get head check for cracks. Which is what I'm doing next week to my 91 Explorer 4.0. Which are known to have gasket problems.

Replace the gasket with gasket glue

That stuff doesn't work. Actually it clogs coolant passage ways and creates more problems and is extremely difficult to get out.

Anywhere you like. It won't work if the gasket has failed

Remove the radiator cap and place another car under it.