Oh sweet irony! (AKA no good deed goes unpunished)
 

Driving home today, I see an old 4Runner packed out at an intersection, hood up, 2 clueless looking people peering under it. So I turn around, park in a parking lot at the corner, and left the Civic running (ya I know, but I didn't know if they had help on the way already or what, so I just hopped out to see if they were ok). Long story short, the lady driving it had it stall, and called the guy to come help, but he was useless. "Did it do anything weird before it stalled?" I asked. "It made a clicking noise, that got louder, then it died." Hmmm, that ain't good. "What did the temperature gauge say?" I asked. "Which one is that?" she replied. Oh boy, that really ain't good. "When was the last time you checked the coolant or oil?" I asked. "I don't know, last year I guess." Good grief. Pull the dipstick - no oil. Take a towel they had and carefully crack the rad cap - no coolant either. So I help the guy push it off the road so we don't get creamed, and turns out he has some oil and a bit of coolant in his car. And the Civic has a mystery leak, so I had some coolant in my car too. I load it all in to the 4Runner, and manage to get it started. Temp gauge still way high, but his mechanic wasn't far away, so I told him just get it there, don't stop for McDonalds on the way. So they both take off.

Walking back to my car, I gave myself a pat on the back for helping them. Get in the Civic, and the temp gauge is wound off the end! Pop the hood, and sure enough the mystery leak finally revealed itself and pumped out about 3 liters of coolant! And I couldn't top it up because I had just given all my coolant to the guy in the 4Runner! Apparently I was overdrawn at the karma bank ha ha ha. :snail:

Now you know where the leak is... right?

The silver lining... now you know where to fix the leak! :p

You know, you'd think that, but it went from no idea where the leak is to "Holy crap there's coolant everywhere and I can't tell where it's coming from!" It's coming from under the distributor, so it's either 1. The heater hose fitting/heater hose 2. the coolant temperature sensor, or 3. the head gasket is pumping coolant out. I'll change 1 & 2 because they are cheap, but if that doesn't solve it, I have a feeling the old CX will be going back to the auction from whence it came. :snail:

It sounds like you need a Mystery Leak Cam. Yay.

The presence of your spare coolant was the only thing keeping the leak under control. I hate that!

Karma owes you a refund.

Good job being a samaritan, there, though.