With such a short wait time I hazard a guess it’s probably a cancelled order that’s already built or close to being built, rather than a new car that’ll be built from scratch to your father’s specific requirements.
Based on discussions over on the Polo forum, lead times on the Polo (all models) are currently around 5-6 months.
A forum member over on golfgtiforum.co.uk recently posted that a family run dealership had told them the lead time on a performance model Golf ordered through them could be as long as two years! A (smaller) family run dealership‘s monthly vehicle allocation from VW is likely to be less than that of a large multi-branch national dealership, so they won’t be able to place as many new car orders per month with the factory as a large national dealership with a larger vehicle allocation can, hence the extremely long indicated lead time. Another forum member on that forum who works for one of the vehicle leasing companies has said Mercedes have currently closed their order books for fossil fuelled cars and BMW have closed their order books.