I take it you told them a taxi would course you undue/heightened anxiety and they just brushed it under the table!
I think I would ring RAC (I believe they sort hire cars) to see if they can help.
If not, I would be putting a complaint into Motability – expressing you were given a car not fit for purpose, as the boot was faulty, which actually trapped your arm when it closed on you. You have exhausted all channels to request a replacement and have no option but to lodge a complaint. Europcar have also told me, they have nothing to replace it with, Yet if I was a private customer Europcar have cars available the next day, and I question if they are discriminating me for being disabled and on the Motability schem. You don’t feel comfortable with as it would not only heighten my anxiety, the length of my jouneys would be unpractical to have one on a daily basis. You thought by signing up to the scheme would ensure worry free motoring, which at the moment you find quite the opposite. To remedy this, you would like a hire car that is not only safe but, also suitable for my needs. You would also like then to look into the shit unsafe car you have been given by Europcar that was promptly returned……..
Your’ll find a complaint, thats handled by the right department all that is needed to rectify the issue and I’m sure reword much of above into something more meaningful 🙂