This paper presents an Electromagnetic Compatibility (EMC) Test Plan and Procedure for automotive electronic components which predicts the EMC performance in a vehicle. Production representative vehicles for EMC evaluation are often not available in sufficient quantities until late in an electronic component design stage where changes are most costly. This Test Plan and Procedure addresses this problem by allowing early detection and definition of component design deficiencies. Also presented are vehicle and electronic component EMC design practices with low cost being a prime consideration. These practices have been proven effective in the most hostile vehicle noise environments on a number of automotive electronic systems.