I tend to agree, based on feedback I've received, that the mystery hose is the drain from the leaking heater core in my SL500 '95. Here's my thought for the quick fix. I don't drive it in cold weather (in Cleveland it snows too) so I would like to know if the two hoses that run of each side of the rear of the motor and into the bulkhead/interior, are the heater hoses and if I cut them and ran a bypass, if that would be an acceptable way to stop coolant leaking out the drain, at least until I can find a way to repairreplace the heater core myself (this entails someone providing me step by step instructions and maybe some pictures for reference)

What do you all think about this temp solution?

thanks, Steve