Dear Glass Detective,<\/em><\/p>\n A very well-known windshield replacement company contends that their aftermarket glass is no different than the Audi OEM glass. When I had my windshield replaced by this company, Audi said that they could not replace the windshield because the glass had internal defects (“ripples”) which prevented the recalibration from working. They presented some diagnostic reports with errors as proof. Who do I believe? What do you think?<\/em><\/p>\n Thank you,<\/em><\/p>\n Rob W.<\/em><\/p>\n Rob,<\/p>\n Thank you for contacting the Glass Detective with your question regarding Original Equipment Manufacturer (OEM) glass and recalibration. The Advanced Driver Assistance Systems (ADAS) that your Audi is equipped with are highly sensitive. The cameras and sensors need a clear, undistorted view, and any defects (like the ripples you mentioned) in the glass that they \u201csee\u201d though could cause them to malfunction and therefore be a safety concern. This is the reason most vehicle manufacturers recommend that OEM quality glass is only used when it comes time for a replacement on models equipped with ADAS<\/a>.<\/p>\n OEM parts are, in theory, the same quality as the parts that came on your car from the Audi factory because they are made by the same manufacturer. When it comes to aftermarket windshields, these windshields must all meet the minimum safety requirements set forth by the Department of Transportation (DOT) designating the glass as AS1 laminated safety glass. However, there are no actual quality standards in place. Fit, finish and clarity may be compromised. It appears that the dealership, especially if they have diagnostic reporting as backup, would be the ones to believe in this case.<\/p>\n -Glass Detective<\/p>\n <\/p>\nAnswer regarding OEM vs. aftermarket glass:<\/h2>\n