I believe there is two months grace period for continuing with a rego on hold.

There is a way round the absurd requirement to pay back rego if the two month period expires - simply change the registered owner who then puts the vehicle on hold - and swap it back straight away. Two lots of $9.20.

Yes the "debt" for back rego may get listed with Baycorp, but when I last complained they simply deleted it from my credit history.

Remember the "debt" is not criminal and there is no practical way to enforce payment.

Police tickets for no rego on the other hand are criminal, but just as for diesel vehicles an occasional $200 fine is cheaper than being legal.