hi, not a kit car,

but check one of my disks out, have vibration i i presume this is the issue, seems pitted how could this have happened binding and overheating caliper?

how longs the car been stood ? Does the disk turn freely by hand or is it binding

Looks like rust buidup from sitting.

They look abit like the disks i have on the locost. Rust build up from standing.

vag rear brakes all look like that sooner or later. They don't work that well and never clear the rust build up from where it's been stood, then they just get worse and worse untill they want binning.

I drive while yanking the bar a bit to clear them off when it's been stood to clear them and prevent this.

Even if you change them though and free up the calliper it'll be a 12 month max before they look crap again

buy new ones and new pads look at the lip on them .or drve with the handbrek on half for a mile that will clean it up

its from my camper van, n/s is fine and been stood the same, done 500miles in the last 3 months and not cleared