I have a Subaru 2003 Forester, do I need...
I have a Subaru 2003 Forester, do I need any additional parts with this rack. I want to use the factor rack.
Your best bet is to go through the Car Configurator at the top of the screen. That will tell you exactly what you need.
Yes, it'll fit. Unless you have a very light bike I recommend getting the adapter cross bars though. The factory racks on foresters are kind of flimsy to support a bike(s).
This rack is only designed to fit on square cross bars. Most factory racks have some flattened oval shaped cross bars. Thule makes an adapter called the ride on to convert from this shape to square. Then the racks will fit.