Vehicle police clearance is something that Interpol might require. It is a document that states that your vehicle is not wanted by SAPS or stolen. Note that it is not the local government, customs or immigration. 

When arranging this it is important to note that you get two types of VPC.

1. When you are moving a vehicle permanently from one country to another, selling or migrating etc you need a type of VPC that you get from your local licensing department.
2. When you go on holiday to another country you get if from the SAPS. This is the one you want.

The VPC takes many shapes and forms and will vary from SAPS to SAPS. You would need to take along the vehicle registration document, your ID and your Data dot certificate if you have one. 

This can be a frustrating process but is necessary. 

You need to visit the nearest SAPS vehicle anti theft unit in your area. Tell them you are going on holiday to Zambia and Interpol wants to see a SAPS police clearance. If you are towing you also need one for what you are towing.

I got mine at the Langlaagte SAPS in JHB.