Total bollocks.

do strongly dislike the term customer.

While you are a "customer" of the DVLA, they're a monopoly with whom you have to deal.

Rather than take the term from business, why not take it from a different service - the Police. Where the term is "victims" - people who deal with a service because they have to.

I have pointed this out before, but I think it is ironic that in order to make government services 'customer-centric' we are obliged to hand over all our personal data including fingerprints. If any other business did this you'd take your custom elsewhere. Short of emigrating this isn't possible...