I would have thought with your Username, User Title and Avatar it would be a pretty easy decision?
Seriously though, Rap Yellow is not a good colour for a GPS. Of the two it is the one you are most likely to regret buying, and is certainly going to be worth less come resale time.
I'm assuming the dealership has both these cars in stock, so are offering you a better deal on those than they would if they ordered one in? If not, there are a few New Orleans Blue left as well, and at least one in Crossover Black.