One of mine had a very similar rear end shunt (at about 2mph). Not quite as bad as yours; panel beat rear quarter, new light and bumper, welded in the small panel below light, respray rear quarter. It was £750 about 5 years back at a VW main dealer bodyshop with all VW parts. The insurance wanted to right it off but I expained to the assessor that it was a G40 not a standard Polo and he was fine with getting it fixed. On mine there was no damage to the boot floor or inner panels at all.