i got a coolent leak but cant find it anywhere ie no puddles on floor etc on 2003 Saab 9-3

cant find the leak no sign of external leak

Asked by for the 2003 Saab 9-3
ck carpet on pass side poss heater core?
Cheers will look tomorrow would a pressure test pick this up?
yes for sure
Oh right i had pressure test and it was fine no sign of loss of pressure
was heater valve open at that time.if not no pressure was applied to heater core
I will check with the mechanic who did test thankyou how is the valve shut off mate ? Can it be by-passed just to check if its that problem