A window deflector is mounted above the doors of some automobiles, to protect the inside of the car from rain or other precipitation in case of slightly opened windows. Deflectors may also be fitted to sunroofs to change the flow of air
Based on the way wind deflectors are installed, they may be classified as follows:
In-Channel
This type of deflectors is installed into the upper window channel, and is kept in place due to tension. In some applications, this type of deflector also employs a thin stripe of automotive-grade 3M tape to keep the deflector in place.
Stick-on
This installation type requires an adhesive tape (i.e. 3M) at the back of the deflectors to mount them securely. This adhesive film allows mounting a deflector above the window (either to the window frames, or to the roof if the windows are frameless).