Models aren't that hard to make. I used to make aliens and monsters to be my characters in The Sims when I was 12, so even a kid can do it

But obviously there are also the textures. Who wouldn't like the ship to have an Angry Faic on the ship, shining in psychodellic colors?
I bet there are alot of very skilled 3D modelers who are also modders AND Audiosurf fans, so we're bound to see lots of awesome new ships as soon as they are moddable. I'm expecting to see X-Wing(Star Wars), Millenium Falcon(Star Wars), Voyager(Star Trek), Arwing(Star Fox), Ghost(Maybe even with Master Chief on it)(Halo), Blue Falcon(F-Zero) and a bunch of other fan-favourites within a week of the patch that allows ships to be moddable is released.(I also expect to see male genitalia and the bird... Thinking of it, the bird could even resemble Master Hand, and Crazy Hand too, on dual ship modes XD)
Also thinking of the dual ship modes, the game could support each ship to have a different model.