Option 1... download and rename it (although this can cause problems displaying in certain browsers)
Option 2 download a icon editor such as the one found at http://ranfo.com/iconedit.html open the file in that and save it to the correct format
Option 3 Change your mind about letting me drive you car and I will email you it j/k

if you want me to email you one I can do, its np... just having dinner at the moment