Vehicle interior harmony has drawn increasing attention from customers in recent years. Kansei Engineering is an effective approach to quantify customers' perception of harmony, and to correlate it to design parameters of the products. Herein, we investigated the customer perception of the visual aspects of commercial truck door interior design using classification methods. This article describes how these visual impressions are related to design elements using quantification theory, a commonly used method in Kansei Engineering. The results reveal that trim material, shape, color, window shape, and map pocket are design elements that strongly affect the perception of “elegance” and preferences of truck drivers. The results also showed a significant difference between the perception of the truck drivers and that of design engineers.