@BluestarE3, you are right. On Oct 28th when he sent this tweet, it was unclear whether the same ice melting technology would be used in cars as well. However, a few days later on Nov 1st Elon said, "It is using a lot of techniques from the automotive glass business and, in case it wasn't obvious with the announcement, Tesla has created a glass technology group with some really phenomenal people" (source). So it looks like Tesla hired people from the automotive glass industry who know about rear defrosters on cars and they have done some tests on prototypes. After the conference call, there were multiple articles about the Model 3 having an ice melting glass roof. This was before his second set of tweets on Nov 4th when he confirmed solar roof on cars: Elon Musk: The Model 3 Will Incorporate Tesla's Solar Roof Technology Expect Model 3 glass to share features with Tesla's Solar Roof tiles The Tesla Model 3 could feature an ice-melting solar roof Quote from the third article: "Musk all but gives away the plans for a paneled roof and windshield that can defrost and melt snow efficiently."