When I first got my car is would leak antifreeze on occassion... I finally had it looked at and they decided I needed a new radiator cap. The problem went away. Now all the sudden it started today. I noticed a puddle underneith my car at school and when I stopped in to work I noticed antifreeze was running out the bottom. I got it home and it quit leaking. Now I can't get it to leak again. The hoses are not wet and they're tight with no cracks. The only thing that is wet it the radiator support. Does anyone know why my car does this? Also, it hasn't done this in at least a year, maybe 2.

 

best way to find this, would be to rent a "cooling system pressure tester", or get a mechanic to do it for you. You screw it onto your rad cap, and pump the handle, and read on the gauge the pressure. Pump it up until you can see it leaking (it's ok to go over normal pressure for a short time to find a leak i'd think.)
I had a small leak I couldn't find before, had my mechanic do this, and watched a tiny hose near my intake manifold go 'old faithful' on me, easy fix.

 

You might want to check the drain plug. This happend to me a few months back. No leaks when the radiator was warm but once it cooled the coolant was seeping past the rubber seal.

 

The whereabouts under the car would be an indication of where to start looking. Water pump weep hole is another thing to consider.

Anything under the hood have coolant "marks" on it? If it's under the hood, and it leaks, it will PROBABLY leave a trail of some sort. I.e. when my water pump went bad, the coolant out the weep hole got onto the crank pulley and threw coolant everywhere. Likewise, when the heater valve broke in half, coolant spewed all over the place under the hood.

 

My 88 would only leak when it was all warmed up. there was a crack in one of the tanks.
When the car was warm, there was enough pressure to push fluid thru the crack.