Nick describes Gatsby's car in great detail, highlighting its luxurious and ostentatious nature. He describes the car as "a rich cream color, bright with nickel" which gives the impression of its newness, brightness, and richness. The car's monstrous length is emphasized through the mention of "hat-boxes and supper-boxes and tool-boxes" which are swollen here and there. These boxes are symbols of Gatsby's wealth and status.
Nick also mentions that the car is "terraced with a labyrinth of wind-shields that mirrored a dozen suns." This description emphasizes the car's grandeur and the multiple reflections of the sun in its wind-shields. The use of the word "labyrinth" adds a touch of mystery, creating an image of a complex and seemingly endless series of reflections.
Overall, Nick's description of Gatsby's car serves to highlight Gatsby's wealth, status, and the luxurious lifestyle he leads. The vivid and detailed description conveys the opulence and extravagance of the car and its owner.