[ITSv40]

This scenario is the very reason why bodyshops don't like dealing with private customers - too much grief for them.

From what you describe the car has had some front end damage on one corner, so bumper replaced, front wing replaced and slam panel repaired to suit. The bumper is bolt on as is the wing so easily replaced. The inner wing particularly at the front behind the headlight is quite thin so easily bashed out to fit. The slam panel is quite stiff so any damage would need to be cut out and replaced, which is what the bodyshop is suggesting.

If it was my car I would want one corner repaired and the minimum cut out and replaced. Why replace perfectly good original metal. A competent bodyshop will know what they are doing and will produce good welds etc.