This ordering extras thing could be just a manufacturers stop gap until their production lines gets back to normal once the virus is history.
We’ve seen the same thing happening in supermarkets where you may only able to get one particular producers product while before the shelves were stacked with alternatives and adding to that where you can only get a 500g box of cornflakes while another times you could get 300g and 1Kg boxes too.
I think the same might be happening with car manufacturers.
Just my thoughts.
Apart from that I think a lot of Motability cars would be unsuitable for the disabled if we weren’t allowed to order extras for the likes of simple things like auto lights or wipers etc. so can’t see Motability stopping the ability to order extras under normal circumstances.