In the nearest town to us, all supermarkets have disabled spaces, all of the car parks do too. All of them are pay and display whether disabled or not. No reductions, just the same as everyone else.
In the town centre itself, there are a hand full of on road bays, where I can park for free, all day. But if I want to visit M&S on the far side of fuck which is very far away, but next to a larger/main car park that is always choc full, I can park on the double yellows outside of the store for free, for up to three hours.
I usually find a space to park in, and pay. However, if I want to go to just one area of the town, I'll try and park on the road or in a bay on the road as near to that place as possible.
Not because I don't want to pay, but because it is the nearest point to where I want to shop which means I can get there, get back and won't collapse!