The VW 2.8.1-1999 standard specifies the material requirements and test methods for resilience materials in automotive structural parts. The standard involves the basic provisions of materials, the evaluation of measurement results, and the marking requirements. The rubber mass of structural parts is tested to ensure that the material meets the corresponding mass standards. The standard lists in detail the marking examples of different types of rubber (such as nitrile rubber, acrylic rubber, EPDM) and their performance requirements. All supplied parts must meet the Appearance mass standard, without defects such as stickiness, inclusions, holes, etc.