“The Trailer Song” is nothing special. But it shows off Kacey’s infectious and endearing wit, and her keen sense of perspective. And it’s catchy, and kitschy, and so very Kacey, and deliciously Country with a capital ‘C’ in both approach and sound. Is “The Trailer Song” a hit? No. But neither was “Merry Go ‘Round”, and it still became one because it was just weird enough to work.