Leaking Windshield Washer tank

Got our new car home 2 and a half weeks ago. Soon after we got it my wife told me the windshield washer fluid wouldn't come out and spray the windows. I told them maybe they forgot to fill it or tip it off. No big deal, she filled it herself and it worked fine. 5 or 6 days later I went out to check the car and the WW fluid level. Son of a B*tch it was gone. As in you couldn't see any in the clear/translucent tube. I figured she just put a little in and I topped it off and told her to make sure she filled it to the top. She swears she did. I checked the car last Friday night. It was missing again. Topped it off for the 3rd time and called the dealer to have them to take a look at it. Wednesday morning came and before I left for the dealership I figured I better look to see if it lost any more or I would look like an idiot for taking it in with no issues. Yup, it was gone again. Looked under the car on the garage floor and there is no liquid. The dealer spent 2 hours looking at it and said there is no leak that they could find and to "keep an eye on it." I told them that I have and it's been topped off 3 times in 2.5 weeks. He shrugged his shoulders and handed me the paperwork. I asked what's the next step. He said you leave the car with us for 5-7 days for us to find the leak. I told them that was fine as long as they had a loner/rental for me to use. My wife needs the car to get to work. They told me that wasn't an option. Asked for the Service Manager who "was out of the office that day." I left a message for him to call me and he magically called me in an hour. I'm sure he was there but the service rep didn't want to pass me off. He told me that if its leaking, to stop in and his techs will take a look. I told him it was just there for two hours and they couldn't find anything. He then asked me where on the floor is the liquid going. I told him it's not on the garage floor. Only a small amount leaks out daily. He told me that I would have to have them look at it again because they can't order a replacement part until they have proof it's leaking and know where. I told him the tech topped off the fluid to the very top. I took a picture. The next morning it's down half an inch. And no water on the floor primarily because the undercarriage is pretty much enclosed. It's not like old cars where you can look up underneath and see belts, hoses, pipes, etc.

I called Toyota and they said they would look into it and get back to me. I'm not holding my breath . Any recommendations on what I can do next or should ask for from the dealership?

Images are of yesterday at the dealership at approximately 9 am and this morning at 530 am. Roughly 20 hours later.