In fact, none of the sponsor signs were changed in the course selection views for the English version! If you look closely at Luigi Raceway, you'll see in the back that none of the signs have changed. In Royal Raceway, the Yoshi 1 logos are still there, and in Mario Raceway, it is small, but you can see the black lettering of the "Luigip" sign. I didn't even notice this or look into it until the Mario Kart 64 j-e page was posted. Too bad they changed them. It would've been hilarious.
"Peachy" he he. :-)