You can add extra Enquiry Sources and Sub Sources to the Enquiry Source drop down and Sub Source drop on the Sales Enquiry window via the Enquiry Source tab in Vehicle Parameters.
To add an Enquiry Source/Sub Source select the Add button. The below window will appear:
Enter the required Description and select Ok to save.
To delete an Enquiry Source/Sub Source highlight the required line and select Delete. This will then remove the Enquiry Source/Sub Source.