The Model 3 sounds a bit like a beta test.
When traditional automakers want to implement a design change or add a new feature, it has to wait for a new model year to come around. Take the 2019 Honda Civic as an example - the car isn't drastically different from the 2018 model but is now offered with an available Sport trim and the infotainment system boasts a volume knob.
Tesla, however, is a very different type of automaker. As the company ramped up production of the Model 3, owners reported various build quality issues on early production cars. In order to solve these issues, Tesla makes nearly daily changes to the Model 3, resulting in interesting differences between early and late production examples.
Since Tesla doesn't like to disclose too much information about its production process, it is up to private owners to detail some of the differences between early and late production Model 3 examples.
YouTuber Teslatunity did just that, using his early production, rear-wheel-drive Model 3 (pictured in grey) and his wife's dual-motor Model 3 (pictured in white), which was built approximately seven months and 95,000 cars later. With only seven months separating these two cars, you'd expect the two to be virtually identical. In fact, Tesla changed multiple details to the Model 3 during this short period of time.
In the video, Teslatunity goes through many of these changes including a garnish on the trunk ceiling, which makes the car look more finished and protects you and your cargo from being scratched by the previously unfinished trunk. Tesla actually sells this garnish for $30 for early Model 3 owners. Next, Teslatunity talks about the car's seats. Aside from the white interior, which was not available on the early cars, Tesla has changed the size, stitching pattern, and rear seat cushion height.
Other minor changes include a switch from a chrome steering wheel badge to a matte one, the removal of Alcantara on the visor mirror, changes to the glass UV coating, and an improved illustration of how to use the keycard. None of these changes would drastically affect someone buying a Model 3 but it is interesting to see them detailed all at once.