Partially automated vehicle systems require the driver to continuously monitor the driving environment and be prepared to take control immediately even when the automated system is performing the steering and acceleration/deceleration tasks. One of the main challenges facing developers of these systems is how to ensure that drivers understand their role and stay alert as the system demands. With little real world data, it has been difficult to understand user attitudes and behaviors toward the implementation and use of partially automated systems. At the time of this study, Tesla was one of the few vehicles on the market with a partially automated system available; Autopilot. In order to understand how customers interact with a partially automated vehicle it was decided to observe people driving their own Tesla’s while using Autopilot. In this paper, we describe a naturalistic driving study that was conducted with Tesla drivers in order to understand their behavior while using Autopilot, what drivers do while Autopilot is active, what influences their use of the system, etc. Results from the study show participants’ behavior, both eye glance as well as hands off times were not as initially expected, both will be described in this paper. Sixteen Tesla owners’ vehicles were instrumented with video / audio data collection systems for three consecutive days. These owners were dedicated Autopilot users who all used the feature daily and primarily on highways. This participant population was divided into two groups; one with 4 months or less experience with Autopilot and the other group with 10 or more months of experience.