This page shows historical data of the total number of new (in existing inventory) Tesla Model 3 vehicle listings available in stock (in the United States) on their website.
Chart via tesladata.mattjung.net by @Mattjungphoto
Browse other new inventory charts: Model S – Model 3 – Model X – Model Y – Model 3/Y – Model S/X – All New (in existing inventory) Tesla Models
Intra-Day New Inventory Dashboard