I have a Citroen C4 Picasso. It was kerbed and the front section of the nearside sill is badly damaged (metal crushed and torn up as far as to where it meets the inner wing section of frame). My insurance company did a sectional sill repair which was very poor. A complaint about the quality, or rather the lack of quality of the repair by an insurance 'approved' repairer was made, particularly the strange blue weld and carbon deposits. I've had my car inspected by a so-called independent inspector (sourced by and paid for by the repairer). I found it to be a hatchet job on dismissing my concerns about structural damage being caused by poor welding of the sectional repair. Other than poor paint finish, the inspector felt there was no issue, even with crushed sill seams visible, bare metal on the underside visible, gaps in the weld visible, and some sort of blue oxidation and smoke/carbon on the underside of the car where the welding was done. I believe there is repair related damage (heat damage to sill and steel floorpan from welding). How can I test for a heat damaged steel structure? Also should the damaged sill panel, which has had only a sectional repair, have been repaired in full?