Multistep Synthetic Monitoring Requests create robust methods for simulating system-wide interactions and transactions. Multistep Requests lets response values from one Step be passed to successive Steps in a single Monitor, creating a chain of requests that can be used to simulate complex behaviors.
The number at the front of the parameter indicates the order of steps in the Monitor (e.g. {{$0.result.cars}} has a leading 0 because it is the first request in the first step of the Monitor).