Rostfall Unterboden Punto 75, Jg. 97

Hello people My wife drives a Punto 75, Jg. 97. At the last TüV, the examiner told me that the rear lift shots were a bit rusty, but not yet dramatic. Yesterday I wanted to tackle the matter and get scared! In the splashing water area of the front wheels in the area of the threshold edge/carrying floor everything is quite attached. When you start to grind and grind, you will immediately find rust infestation under the still well-seeming underbody protection! the underfloor and the overlaying sheets/parts in the connecting edges are rusted so strongly that the ground is rusted in 3-4 places. This is incredible, considering that the vehicle has only 7.5 years on the hump and is often washed especially in winter. I would be interested in your experiences, especially with the punto and rust. Thank you for your numerous answers and greeting Wolfgang