Market sizing: how big is California's Tesla Model 3 fleet?

Estimate how many Tesla Model 3 cars there are in California. Walk through how you structure the estimate, call out each assumption, and finish with a figure and a sense of how confident you are in it. ```hint Think about how a car enters the count Choose whether to start from the cars already on the road or from the cars sold each year, and notice which of your inputs changed a lot over the time the Model 3 has been on sale. ``` ### Clarifying Questions - Should the count cover Model 3s registered to California owners, or every Model 3 physically in the state at one moment, including visitors and unsold inventory? - As of what date should the estimate hold? - Do rental, ride-hail and company fleet cars count along with privately owned ones? - Is an order of magnitude enough, or does the answer need to land within a factor of two? ### What a Strong Answer Covers - A scoped definition of what counts as a Model 3 in California and as of when, settled before any arithmetic - A top-line equation that links sales or the vehicle stock to the count, including how cars leave it - Labeled, round assumptions with a rationale for each, and a view on which inputs shifted over the car's time on the market - Arithmetic that is correct, unit-consistent and easy to follow - A cross-check from a second angle, a final range, and the inputs that move the answer most ### Follow-up Questions - Which assumption moves your answer the most, and how would you tighten it? - What public data would you use to check the figure? - How would you adapt the estimate for Texas, and which inputs would change the most?