[Mr.Fox]

In your MODS folder create a folder. Name it for example "Freddie P51". Then open it and create a folder named "3do". Open the "3do" folder and create a folder called "cockpit". Open the "cockpit" folder and drag&drop the "P-51D-20(K14)" folder from the rar file into it. It should be like this at the end:

C:/Progs/Il-21946/MODS/Freddie P51/3do/cockpit/P-51D-20(K14)

Hope this helps people who aren't really familiar with the order of folders.

Mr.Fox, the above procedure fixed the problem for me, hope it works for you.

hm, thats the exact thing I did. word for word. I'll try deleting and doing it again.
but just incase it doesnt work, anyone else know?