Stumped! How Do I lock the Windows ?

[DwightKSchrute]

Maybe get a cover like this? Below is just something I googled and is unlikely to fit the Model 3, but just an idea.
Car Window & Lock Control Cover Pet Lock You Out - Etsy

You can probably make a makeshift one for cheap from a wall plate cover (may need to make a paper template and cut one edge with a hacksaw). Then secure with either tape or velcro (or looking at 3d printed version, get a square dowel that fits into the slot of the switch and glue to the bottom of cover).
Leviton 1-Gang Midway Blank Nylon Wall Plate, Black R55-0PJ13-00E

I see in other thread people just make it out of cardboard which is even easier (just need a box cutter and some spare cardboard). Some made a 3d printed one that fits perfectly, you may be able to get a local printer to print out the design for you.
My dogs keep opening the windows!

I cut a piece of cardboard to approximately fit the opening. My dog has learned to open the windows and is rather territorial about people approaching the car. Thank goodness for Tesla not requiring a gas station.