With so many new car models frequently being added to the road and Volvo being one of the least talked about makes, maybe they felt that in order to get noticed, they needed to create a negative design that would turn heads and get people talking. They created a statement.
The advertising concept involves the audience and asks their opinion. They also work on the idea that you either love it or hate it (a bit like Marmite!) Comments like, "...That's one opinion - what's yours?" and "Design creates debate" enforces the idea that Volvo has aimed to make an impact.
This proves that a negative response is as powerful as a positive response.