Well if its a *.cup.car file
All you have to do is copy it to the papy\series\cup\cars folder and the
next time you start the game it will be in the list for you to select.
If its a tga file
Copy the tga to the imports_exports folder. Then start the game goto
opponent manager and create a new car file. Select the correct make give the
file a name and say ok. Then open the paint shop and select import. Choose
the tga file you want and hit ok. It should lok like the file you
downloaded. Save and Exit paint kit. Enter the driver info and car # and
save again. Now all you have to do is goto the player info and select it
from the list and its ready to go.
99% of the car will be the car file method so its really pretty easy.
MadDAWG