I have recently discovered that spore creations can be imported into XSI.

In order to do this, you begin editing the creation you want, and then press Ctrl+Shift+C

Then you type "colladaexport" and it will export it to the mysporecreations folder.

Then you open XSI and select File, Import, Model

Use the drop down menu to select .dae.

Then find your creation.

You might want to turn off nulls.

If someone could figure out how to remove the mesh from the skeleton, this would be a great way to get advanced vehicles into SWBF2.

Problem is, I'm worried this might be illegal...

AFAIK the Spore EULA says that its illegal to use the models in other games. I think it already was discussed here somewhere.