Anyone know how to get the invisible numbers off the front windshield. They show up every time it rains and gets fogged up and their on the drivers side. There are 4 lines of numbers.

 

Has this car been purchased recently, after being run through an auto auction? If so you are probably seeing leftover residue from the winshield markers used to give consignment info such as owner, auction id number, mileage. Similar to china markers, could try alcohol, or carefully solvents, or maybe rainex if it was a wax base marker.

 

Glass cleaner and steel wool should be able to remove all the oils leftover from the marker used.