Once you open your agreement, you'll be able to change the vehicle. When you switch vehicles however, the inspection out is cleared and the agreement goes back to a draft state. You'll need to finish editing the agreement and open the agreement with the new vehicle selected.
This article will show you how to switch vehicles.
1. Select a an Open agreement
2. In the Vehicle card, search a new vehicle with the search bar
3. Select the new vehicle
4. By switching vehicles, the inspection will clear out and the agreement will go back to draft state
5. Review or add an Inspection Out for the new vehicle selected
6. Click Open to put the agreement back to Open state with the vehicle