Will 2003 ktm 65 sx body plastics fit a 1999 ktm 65 sx?

No, the body plastics from a 2003 KTM 65 SX will not fit a 1999 KTM 65 SX. While both models belong to the same family of bikes, significant design changes and variations in mounting points occurred between those years. It's best to use parts specifically designed for your model year to ensure proper fit and functionality.