I tend to go soley as a customer in the first instance. Once I have narrowed my choice down, only then do I go back and suggest I’m a Motability customer. I find doing this way alot easier!
If there was anything I was uncertain about on my initial test drives, I will often request an extended test drive on Motability’s insurance. DLM allow 24hrs but, has to be arranged via the dealer with DLM. However, I have always took the car back after 3-4 hours anyway. FWIW RSAM use to allow up to 48hrs.