Replaced a cracking coolant reservoir with a new one + cap and think the added capacity to hold pressure exposed another leak.

When filled to the "min" line my car will start leaking coolant on the passenger side, just above the transmission. I visibly identified a flowing leak onto the transmission from behind the firewall here after a drive with freshly filled coolant.

Coolant level will hold steady at a good 2-4cm below the empty line for a while, so the leak may be at a fitting or something that slows down with less pressure.


Anyone know of what to look for here? I think of the b6 there is a pipe here? I'm thinking without a Bentley manual it will be hard as I can't really see up there even from underneath and its a bit dark for mirrors.
Heater hoses? Pipe?