According to the post on their blog, The Brahg:
We recently had a fun opportunity to work with Fiat on custom graphics for a Fiat 500. The car is being advertised as an economical vehicle that can take you out of the city and deliver you to the mountains, so we kept with that theme and created a mountain/snowboard related graphic. The design is a mix of our classic Chairlift and Wa Brah graphics accompanied by new artwork representing the most iconic mountain in the region: Mt. Rainier. The car is currently on the showroom floor at Fiat of Tacoma.
Also included on the back of the car is the 'NW' logo that has become a staple in the company's designs and borrows from the trident-fork M that was part of the Seattle Mariners' logo during their early years.
More photos of the car can be seen on Casual Industrees' blog.