Any one know where the drain is for the Battery compartment for an 99 A6? Full of water then it leaks like a sieve inside the car. the whole foward plenum area is full of water? Help! thanks

 

There are two drains that tend to get clogged with debris (leaves/pine needles/etc.). Remove the battery. Underneath the plate that supports the battery is one of the drains. The other is to the right of it when looking from the front (towards the driver's side).

Once you've cleaned them out (pressurized air may help), check the area twice a year to make sure it's free of debris).

Good luck. Stay on this -- that water flowing into your passenger area can trash your electronics.