rear disc plates (Picasso)

[871thompson]

Can you tell me why the rear disc plates are scored on the inside surface only

[asbo1]

Normally the inside of brake discs are protected by a backplate and usually a stone gets flicked up in there and stas ther scoring the disc until it's ground away small enough to fall out

[Toureman]

This must be the side where the caliper pistons are putting pressure on the disc, perhaps your sliding caliper is sticking and not putting much pressure on the other side where there is no scoring.