The window grille(
: Takalasin ritilä) is a car part which can be bought from the parts catalog at home for 219 mk.
The window grille is more specifically a car window louver that can be attached to the rear window of the player's Satsuma AMP without any bolts. While appearing from various external angles to obscure the view of the window, the louver's slats are specifically angled to allow for the best amount of visibility through the rear window from the driver's position, appearing nearly flat when the driver looks back or sees through the rear view mirror. The part can be recolored by using spray paint.
The window grille is a required part to upgrade the Satsuma to a GT variant.