The purpose of this study is to reveal concrete evidence on how aesthetic preference is applied in product design by countries. Since the 19th century, the proportion has been examined various times, and the conclusions consistently showed the strong preference for the golden ratio (1:1.618). However, previous studies are mainly focused on western products that were designed by western designers, so when the same experiment conducted for the first time in Asia with the question of ‘Is the Asian subjects also likes the golden ratio?’, the result clearly revealed that Korean subjects have a significant preference for the root ratio (1:1.414) and perfect square (1:1). It demonstrates that proportion preference might be different by countries, and it also influences on everyday products. Moreover, there is not enough evidence of Asian product proportions. For this reason, this study will strive to expand the knowledge on Asian aesthetic preference by focusing on Japanese automobiles that were designed and produced in Japan. 55 iconic Japanese automobiles were analyzed for proportion and compared with 50 iconic German automobiles. The result shows that Japanese automobiles have a shorter length of 7:10 (1:1.414) ratio than German automobiles with 13:23 (1:1.769) ratio. This result proves that there is the difference in preference for the proportion of Japan and Germany, and it has already influenced on automobile proportions. This result has a strong value that finding the most appropriate proportion of automotive design is a major issue in new product development, so this can be adapted to various fields of the design process where strong cultural value exists.