The use of simulation tools by vehicle manufacturers to design, optimize and validate their vehicles is essential if they are to respond to the demands of their customers, to meet legislative requirements and deliver new vehicles ever more quickly. The use of such tools in the aerodynamics community is already widespread, but they remain some way from replacing physical testing completely. Further advances in simulation capabilities depend on the availability of high quality validation data so that simulation code developers can ensure that they are capturing the physics of the problems in all the important areas of the flow-field.This paper reports on an experimental program to generate such high quality validation data for a SAE 20 degree backlight angle notchback reference model. This geometry is selected as a particularly powerful test case for the development and validation of numerical tools because the flow exhibits a realistic impingement and A pillar regime, significant three dimensional structures and the backlight/boot-deck exhibits a local separation and reattachment. The paper includes force and moment data, surface pressures for the centerline, slant, boot-deck and base and detailed PIV data for the impingement region, model centerline, A pillar and multiple planes on the slant and boot-deck. Time averaged, statistical and instantaneous data are presented.Results are discussed with regard to the overall flow features, the correlation between the different data sets and the accuracy and limitations of each of the experimental techniques in this particular application. Example data is included throughout the paper and full data sets are freely available in the Loughborough University Institutional Repository as a resource for future code development.