You may use the split invoice when the customer wants to purchase a dealer option item rather than it go via the finance.
Do this - go into the vehicle stock record and on the top ribbon select the "Configure Split".
A window similar to the below will appear:
On the right-hand side select the option for "New Split". The customer search screen will then appear.
Search for the required customer and double click - the system will then take you back to the configure split screen.
Double click the line that you wish to bill to the customer, and a window similar to the below will display:
Enter the value under split 2 and select "Don't Charge" next to Split 1.
Select Close to save and the close on the configure window.
When invoicing the deal, it will generate two invoices. An example is shown below: