Rear wiper in a sedan: unusual feature

Spotted this 2nd-generation JDM Toyota Allion with Paraguayan registration yesterday in the afternoon on Jurerê Internacional beach, in Florianópolis city, Brazil. Immediately the rear wiper, which is an unusual feature in sedans available through official sales channels in South America, caught my attention. It's often claimed that a rear wiper is redundant on sedans because of the aerodynamics preventing water and dust to accumulate while driving, but it might be actually worth, as it may help removing some small layer of snow when the vehicle is parked outside overnight, and also improving visibility while maneuvering in reverse.