Cant find my leak?

[wheredoesthisgo]

Hi folks, i have a 93 4afe engine that i have to put about a cup of water in the radiator after about 150 miles (all highway). I can not find the dang leak. I had a friend follow me on the highway at 60 mph and he said no white smoke, I suspected a head gasket. No milky oil. No drips in the diveway. It does leak out of the drain near the glove box when i run my ac but that looks like the ac evap drain and its not green. I hear it gurgleing into the radiator expansion tank after 150 miles but never spews out. Anyone know where the heck this antifreeze is going? Nothing wet in the engine compartment. I replaced the lower thermostat hose and the thermostat. But like i said nothing ever wet in the engine bay. No steaming out the cap. I am stumped. its a drag having to check the rad all the time. Thanks in advance.

[Rip The E Brake]

leaking out the bottom in the rad... they tend to crack there and the leak runs along the rad support.