Areas that rust - Behind VW underseal

This is a general description of what can be found behind apparently good looking original VW underseal, once a chink is seen and it is stripped back for inspection...

This case happens to be typical of front jacking points approached from the wheel-well and rear cross member/jacking points also approached from associated the wheel-well.

Front:

A good tool to clear away underseal is a re-shaped wood-chisel