Solved miramar left fender becomes chrome

The error went from your modified glass jbeam, you have an unclosed DeformGroup, so when the windshield broke, it's apply the deform group to the next part, you just need to add :

Code:

{"deformGroup":""},

to your flexbody section of glass :

Code:

"flexbodies": [
         ["mesh", "[group]:", "nonFlexMaterials"],
         //glass
         {"deformGroup":"windshield_break", "deformMaterialBase":"miramar_glass", "deformMaterialDamaged":"miramar_windshield_dmg"}
         ["miramar_windshield", ["miramar_body","miramar_windshield"],[]{"deformSound":"GlassBreakSound1", "deformVolume":0.7}],
         {"deformGroup":"windshield_break", "deformMaterialBase":"miramar_glass_int", "deformMaterialDamaged":"miramar_glass_int"}
         ["miramar_windshield_int", ["miramar_body","miramar_windshield"]],
         {"deformGroup":"windshield_break", "deformMaterialBase":"glass_invisible", "deformMaterialDamaged":"glass_mirror"}
         ["miramar_windshield_dmg", ["miramar_windshield"]],
         {"deformGroup":""},
    ],