I think it's the '*' key on your number pad that prints the screen to a
pcx file. Then you will have to use a pcx2bmp convertor to make wallpaper
for windows. Try the shareware program 'Graphics Workshop'. It's
available at many anonymous ftp sites. I think that you can get it at
ftp.cica.indiana.edu. If you have Corel draw, you can use that to convert
the file also.
Try that '*' key (I don't think <shift-8> works) and you should see
something like a nascar01.pcx file in your nascar directory.
I haven't tried it in a replay though but I know it works when racing.
Hope this helps.
Ujjal Bansel