I've downloaded several of the buildings in the file library, and have poked around their contents.
The building textures seem to be mapped to portions of an included ACE file, and I'm wondering how difficult it would be to, say, scale up the size of the included ACE file and improve the resolution of the finished product.
For instance, the Clark service station model's textures are entirely contained in a 512x512 pixel file, and I'm thinking that this could be bumped up substantially without lagging a modern processor.