Poli i definitly agree with you my freind but it dosn't solve my problem consisting in working on only one mesh not all of them how i'm supposed to proceed to preserve other stuff in their original texture and forms
for ex in this case if i need to work only on the fender what i m supposed to...
thank's CuriousMike another question some meshes changes names when imported in Blender why ? for exemple when i imported the gas tank mesh i got material text face addons mesh