beldecal makes ink-jet decal paper..
But you've got 1 of 2 problems, depending on which way you go.
If you use the clear paper, you can only put them on a all-white car.
You can use white paper to print your decals, but you will have to cut them out PERFECTLY, or the white edges will stick out like a sore thumb.
Hope you're good with an X-Acto blade