There's no parking permits in that area, but being at Crystal Peaks by car for more than 4 hours essentially puts you in a position that you have a parking permit as you'd get a ticket if you are there for longer or move to another car park. So that's why I park in an estate sometimes haddy.
On hot summer days shopping centre's are always quite so you'll easily get parked. I got parked next to the main entrance at Meadowhall yesterday very easily.