Matt Stewart shares his experience of using Grafana Cloud to monitor his Tesla Model 3 by leveraging Tesla APIs and a Teslafi account. He outlines the process of setting up a Raspberry Pi with Prometheus and Grafana Cloud to visualize various car metrics such as charge state, miles driven, and OTA updates. Through a detailed step-by-step guide, he explains how to install necessary software on the Raspberry Pi, configure Prometheus to collect and export data, and use teslafi_exporter to gather data from the Tesla APIs. The setup enables users to monitor Tesla data within Grafana's dashboard, showcasing the flexibility and capability of Grafana Cloud for diverse monitoring applications.