The use of Expanded Polyolefin foams including Expanded Polypropylene (EPP) material for interior applications has grown over the years to include applications throughout the vehicle. The demand for weight and cost reduction has forced designers to seek out the most versatile material available to satisfy the need for performance, durability, as well as design flexibility. The role of light-weight materials such as EPP has expanded. As such, the design challenges have also enabled the use of EPP in applications requiring energy management, as well as structural, acoustic, and storage/stowage functions.This paper will review the design guidelines that enable EPP to be used in numerous automotive interior applications. As EPP foam becomes more widely specified, and as the applications become more multifunctional, it is important to understand the potential solutions available to satisfy all aspects of design, performance, quality, and safety.Recent material developments and innovations allow for EPP to be specified in a wide range of densities, and with a variety of surface finishes and textures, as well as surface properties that allow it to be used in applications subject to NVH (Noise, Vibration and Harshness) requirements, and those requiring material compatibility.Technical innovations now allow for material optimization, which enable EPP to conform to the stringent performance requirements and BSR (Buzz, Squeak and Rattle) guidelines for today's automotive interiors. Performance can be affected using either mechanical or chemical solutions to satisfy OEM requirements.This paper will also highlight current production examples of EPP applications and their latest design and performance characteristics. Examples of recent performance studies will be cited; including graining and textured surfaces, acoustic enhancements, low friction solutions, and molded part operational and attachment methods.