The thermostat housing. I've got a 05 R52 non-s and he's been leaking coolant for a while now. I noticed a week ago and took out the battery box and CAI to get a better look. Found the leak here (kind of a bad picture, but just look for the green) :



I replaced the thermostat and the gasket that day, but the coolant is still leaking out although not as much . I didn't see any cracks/warping/oddities in the housing, but I guess thats my next step. I also remember reading (on NAM?) something about an aluminum version of the housing instead of craplastic? Any thoughts, suggestions, advice? Thanks guys!