I told you I had a solution. I’ve been liberally cribbing sprites from The Shyguy Kingdom. Specifically their Mario Kart Super Circuit page.
Using this sprite sheet I put together a 3d view of Mario on his go-kart and converted it to the SRF format needed for use on Garmin Nuvi’s. Not only that, but I’ve done it for every driver in Mario Kart Super Circuit for the GBA.