Not Motability related but when we were expecting our first child I made the decision to get the biggest transport system on sale, a hybrid system as comfortable off road as it was in a shopping centre, it cost a fortune and would grow with my child, pram, pushchair, you get the idea. Anyway when we got it home and assembled the beast, it would not fit in the VW Golf, so I did what came naturally and went car shopping.
I guess sometimes taking a step back and looking from different angles is advised. I loved that Golf, replaced it with an A class Mercedes that had windows that would drop on their own accord, particularly on rainy days.