thats the bit that says you can buy the car.
I never said you can’t.
This is legal guidelines, you need to differentiate between purchase, usage and registration. They do, in fact, too – as clearly shown by the last paragraph under 3.4 where they specifically talk about registration, not purchase. When they speak specifically about registration, they quite clearly state that there needs to be a legal reason as to why the disabled person wouldn’t be able to register the car. Again, this would be open to abuse otherwise.
That just means that an appointee can go and buy the car. It still has to be registered to you (or, his wife, in that case).
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.