On topic, we put money away over the three years, as we see fit. We got a separate account for “car stuff” (like valets, equipment like halfords boot liners etc), and whenever we feel like it, over the three years, we chuck money in. Never really huge lump sumps, always a 20 here, 50 there, sometimes 100, sometimes (albeit rarely) 200. As we have it.
It’s our first car, so we didn’t have a GCB to start with – but the GCB will go into that account too.
Really doesn’t make sense to pay motability monthly to “build up” an AP, might as well just put it aside. Neither is motability paying AP, and you pay them monthly back (if i ran motability, i wouldn’t offer it either).
It’s basically just, you know, being frugal, saving over three years – and then after three years see how much you got, and choose a car accordingly. If your disabilities have certain requirements that you can’t afford, motability themselves help with grants.
That of course doesn’t include “i can’t afford the car i want“, it’s only for the car you need. As it, imho, should be. If you want a luxury car, you either can afford it or, well, you can’t. Tough noodles. But if you for example need a 7 seater and can’t afford the AP for a 5008 or similar, that’s where they help.