Placement on Vehicle: Left, Right, Rear, Windshield. Clean the surface area of glass. Make the measure of double-sided tape position of the louver on the rear windshield. Peel of the tape and stick it on the glass.Align on the tape position to finish the installation. No need for drilling or modifications. No need for tools, just hands. 1PC Rear Window Louver & 2PCS Side Window Louvers. We will reply you in 24 hours.