Answer:
From the main screen, enter Vehicle Configuration.
Create a New Configuration and select Custom build your own from the configuration selector.
Select OSOM and build a vehicle that best represents your requirements.
Save & Exit, then Apply for a new permit application using this configuration.
In the Permit Application, you can enter any additional information into the comments field under Step 6 - Confirmation of the application process. There is also an option for your to upload any photos or diagrams of your vehicle configuration in Step 4 - Attachments. For more information see the User Guide.