Love The Drive Lexus IS 250 or 350 Wind Deflector 2009 to 2015 - Manual (Page 2)

The rear brackets will lock into place around the
head rest seat posts. Turning the thumbscrew
towards the drivers side will tighten the screws.
Turning towards the passenger side will loosen
them.
The rear brackets are then turned to 90
degrees so they will lock into place with the
rear seat head rests. See next photo.
Next, extend one of the front barrel bolts to
the out position and lock it. The bolt is locked
when the handle faces down.
Standing beside the rear seat, lower the wind
deflector into the backseat and insert the extended
barrel bolt into the hole in the rear trim panel on
the opposite side. The rear brackets will rest on
the rear seat. Then extend the other barrel bolt
into the hole closest to you.