I'm pretty cheap so I think I would order a cheescake selection from Omaha Steaks. It should come packed in dry ice. Better ask them if it will have the ice. When it arrives, break off a piece of the dry ice and watch the vaporizing CO2 leave a visible gas trail. Using tongs or pliers hold a small chuck of ice up around all the tubes and determine where the gas is being sucked in, if that is the case. Maybe a flashlight or a lazer pointer would help illuminate the gas. Regardless of whether this helps with the car you can always eat the cheescake and have some nice hot coffee while you try to figure out what to do next.