the dashboard how to fix it? The windshield fogs with warm vapor coolant that exits from the outlets ducks under the dashboard.

if you try some of that radiator stop leak, it may stop your leak. it may also stop all antifreeze from going to your radiater. i've heard that crushed black pepper works.

You probably have a leaking heater core. Not sure on the Audi, but most are a pain to replace. The part may be 40, or 50 bucks, but it may cost a couple of hundred to install it.

You can by-pass the core. Under the hood there will be two heater hoses going into the firewall at the heater core inlets. Remove both hoses and connect them together with a suitable diameter of pipe and clamps. You will not have heat in the car, but you won't have a leak in there either.