"Sunshine Girl" by Upchurch is a song that celebrates a girl who brings happiness and light into the singer's life. The lyrics depict her as a source of joy and beauty, with references to her Instagram name on her car window, her presence in the shotgun seat during summertime, and her sweet lips tasting like honeysuckle. The song also describes her rebellious nature, sneaking out late at night, and the feeling of infatuation the singer has for her. The chorus emphasizes her importance in the singer's life, describing her as his sunshine girl and the only perfect ten he sees in the whole wide world. The song further illustrates their love and connection through romantic imagery, such as slow dancing and gazing into each other's eyes under the moon and stars. Overall, "Sunshine Girl" is a love song that celebrates the singer's admiration for a girl who brings light, happiness, and excitement to his life. It portrays her as someone who is carefree, rebellious, and deeply cherished by the singer.