The issue of moving from a mass production operating mode to mass customization, or even limited customization, has many companies struggling to reorganize their product architectures. Enabling the production of several related products for different market segments, from a common base, is the focus of the product variety design research area. In this paper, the applicability of product variety design concepts to the design of automotive platforms is explored. Many automotive companies are reducing the number of platforms they utilize across their entire range of cars and trucks in an attempt to reduce development times and costs. To what extent can research on product variety design apply to the problem of platform commonization? This question is explored by comparing product variety design concepts (standardization, modularity, mutability, etc.) to platform structures and requirements. After assessing the applicability of these concepts, a platform representation and methods for measuring platform commonality are proposed that incorporate key characteristics of these concepts. An application to two platforms is included. Although preliminary, this work has led to insight as to why automotive platform commonization is difficult and how product design variety research can potentially aid commonization. The findings are potentially applicable to product platforms in general.