Does anyone know the process involved in registering a car that is missing id tags?????

I have chassis and engine numbers but so far have come up with nothing in any checks i have done and all phone calls to relevant authorities are leading to dead ends.

i keep getting told that it needs to go through a regency (S.A.) check but don't want to fork over my cash for a van until i know it can be registered any idea's on this prob would be ace.

Cheers Dan.