Carbon neutrality has attracted global attention. Carbon emissions from the transportation sector are the second largest emission source globally, with passenger vehicles being the primary emitters. The carbon emissions of automobile parts largely affect those of the whole vehicle. This study constructed a carbon footprint accounting model for automotive parts based on life cycle evaluation and accounted for the carbon emissions in the four phases of raw material preparation, manufacturing, use and maintenance, and end-of-life recycling. We considered a bumper produced by PW Enterprise in China as an example to conduct an empirical study. The results of the accounting showed that the bumper emitted the most carbon emissions in the use phase. Finally, two-factor sensitivity analysis was conducted, in which the total mass of parts and mass ratio of component materials were analyzed as the two changing factors; the results showed that total carbon emissions varied when the ratio of engineered plastic materials was changed. The method developed in this study can analyze carbon emissions during the life cycle of automotive parts and will aid enterprises in selecting green material types and determining the quality ratio while ensuring product performance.