One way these guys from a particular background drive round in flash BMs and Mercs is to register themselves as car traders with a group of mates, call themselves directors and then pool together the insurance that allows them to drive anything, anywhere and at anytime for reasonable money. If they happen to do a bit of trading on the side they are also covered as one of the crew will have some premises registered. They are also able to drive round without tax as the car counts as 'in trade'. The company does not even have to make much money as it exists to allow them to drive round in cars they would not otherwise afford.
So next time you see some young lad in a flash car, and think 'How can he afford that?' This is how.
And having a family member who is disabled and so qualifies for Motability scheme and seeing as nan lives at home with the family, its easy. No nan? no problem, having a kid with ADHD also qualifies so you can still bag a car (hence the explosion in kids 'suffering' from it, very little to do with air pollution, gender bending chemicals or food additives). Also helps if your doctor is your cousin.
Gone a bit off topic, but this is how these guys operate.