My Mrs scrapped her i30 on the 27th of Feb, filled in the online form on the DVLA website on the 4th March and recieved written confirmation fromt he DVLA that she was no longer the owner yesterday so that all seems reasonable.
No new V5C to print though.
Years ago I sold a Metro and all the paperwork went through quickly. Almost a year later I got a letter from a council in Norfolk telling me that if I didn't remove my abandoned Metro I would be charged for it's removal.
I made a call to the Council in question (don't now remember which one), and was told that the database used by councils at that time can take months to update. This was probably the late 90's. What was particularly odd about this was that the Metro in question was a low mileage Turbo, so maybe it had been crashed and abandoned. It was too far away to bother going to see.