Nice detective work Orion.
Warm water clean out…. I will remember that trick !👍🤓

 

I think the jury is still out on this one.

 

We just washed the car, not a drop came down. Not on to the paper towel (kitchen roll) we have on the floor, or on the plastic panel under the heater core where the water drips either side out of. We have taken in for a run to see if that will bring any down. Again, here's hoping. Just came back, wife was driving, she always gives it some stick and nothing. Verdicts in!

 

 

The big question now is how do I make money off my big discovery?

 

You assemble a few eBay or Amazon parts that you can call a “kit” place in a well decorated point of purchase box and call it Automotive sunroof and water drain and tubing declogging kit.

 

Yeah...
Don't know about your parking area but under pine trees (spruce likely as well) can be an issue.
A friend's driveway and garage, garage is full of canoes, kayaks, bicycles, tools etc. leaves no room for vehicles, is surrounded by pine trees.
Certain times of the year the pitch/sap will run and land on vehicles and can/has clogged his drains.
The warm water trick works well to remove the sap/pitch from the vehicle and the drains.

 

Not many pine trees around here but we did have a fir tree with needles but no longer. Yes I think a needle could get through that hole but probably not. We do get a lot of yellow pollen on the car which can get sticky when wet. We thought after we had cleared it yesterday that we did wash the car a few times since all the pollen, but it still plugged up. Then we realised that washing the car with warm water will not have the same effect as pouring very hot water directly into the drain hole. Maybe that made the difference?

 

The warm water will definitely loosen the congealed/hardened sap if there is any there.
Cold water just makes it harder.

 

I agree, and I'm sure that if we had poured warm water directly into the drain hole it would have had the same effect. But when it has been on the roof and windshield first , when we wash it, it would only be barely lukewarm.