Has anyone tried to change incorrect vehicle rego info?

[gjm 3258]

I was talking with someone about this yesterday. He has a vehicle which has passed several WoFs without issue, yet on inspection probably shouldn't (from a documentation) perspective be on the road. Esentaily - the chassis number is fundamentally wrong. Everything else is correct and there's nothing that seems amiss, but the VIN suggests it's a different vehicle to the one it is described as.

I've seen similar in other circumstances, including a vehicle accurately described and with rego number matching that on rego plate and database, but with a VIN for a different vehicle.
The VIN plate on the vehicle displayed a different rego number (stored in the NZTA database for a vehicle matching the description) and a chassis number which was correct for the vehicle.

Is it possible to rectify this situation? Theoretically a WoF inspector will pick this sort of thing up, but how do you then go about reconciling the physical and documented records?

[E30 325i Rag-Top 2958]

Yes, have done similar a number of times. 

MR16 form and lots of supporting documentation. It helps if you can point out (without blame) how and where the error occurred.

if successful a note is entered on the MVR linking the new VIN to the previous one I believe.