Last week I asked about a "STOP: Check Coolant" message on the OBC. I added coolant and the message disappeared, so that was simple enough. Now it appears I'm losing coolant somewhere. The reservoir is already quite a bit lower than when I refilled it the other day. I've never seen any on the ground around my car however I occassionally can smell antifreeze when I get out of the car. Just a quick whiff then it's gone. Any ideas? I'm guessing whatever it is pretty bad.