A market sampling of motor vehicle lighting devices and seat belts approved for sale in California found a sizable percentage not complying with State requirements. Samples of 40 different devices, in both after-market and original equipment categories, were purchased on the open market and subjected to the same inspection and test procedures as the corresponding samples originally submitted by the manufacturers for approval. A large percentage of the purchased devices were found unacceptable. Many of the unacceptable units showed obvious physical changes made in production when compared with the original samples submitted for approval testing. In the remaining unacceptable devices, performance deficiencies were probably due to inadequate quality control in manufacture. There was no significant difference between the after-market and original equipment categories with regard to the percentage of purchased devices found unacceptable.