Yes, "marketing" was a poor word implying this will be for sale. It is however, as you stated, promotion of the university and the team.

While the project as a whole, the materials design and the car as a whole is absolutely fantastic, the carbon filtration part is a deliberate promotional gimmick that has no other academic or pratical purpose.

The statement by the team lead from the article: "We are cleaning the air while driving" and the fact that they put the filters in the car, most likely knowing they are just making it less efficient points to the idea that it was something done to catch attention (and was obviously successful to some degree). That is, of course, both an understandable and often necessary thing to do to promote the university etc.

I just wanted to remark on how pointless of an addition to the project car it is.