As per the title - once an imported car has had its IVA inspection, how long does it take DVLA to complete the registration so you can start using it in the road?
Uusally within a week, number plate cert arrives first & away you go, then V5 some time after that. Though it now all at the mercy of the DVLA feckwits so dont quote me!
Within a week They were promising an SLA of a 2 week turnaround, that then got degraded to "we aim to..." Might be better in the winter, but registrations after IVA last year, mine included, seemed to be running at 4-6 weeks. Still you might be lucky