Figuring out the location from the clue, and collecting the chassis, will allow the player to collect the other four parts required for building the 1965 Chevrolet C10 Sidestep Pickup. The individual locations of the parts will be given to the player in the form of four clues;
Collecting all five parts will allow the player to built the 1965 Chevrolet C10 Sidestep Pickup at Rav's garage on Airfield 73.
The Sidestep chassis can be found at the roadside at the top of a gorge in Silver Canyon.
Nearing the part will trigger a sonar beep, and will increase in rate as the player nears the part. Collecting the part, once prompted, will deliver it to Rav's garage on Airfield 73.
The player is required to complete the Tyler: Riot Club questline in chapter 3 - City Lights, before they can collect the chassis.
Collecting the chassis will deliver it to Rav's garage on Airfield 73, and will give the player four clues that point towards four other parts required to build the 1965 Chevrolet C10 Sidestep Pickup.