There have been a number of posters who read the box and see Taiwan, rather than reading the label on the bottom of the camera. The box may list Taiwan due to the 18-55mm lens being made in Taiwan.
When I bought my 300D in 2003, and the body was made in Japan. I have photos of the camera, but not the id plate.
Never had a 300D, but here's a picture of the 300D with a "Made in Taiwan" tag at the bottom. It's near the bottom of the page:
Again, there are both MIT and MIJ versions of the camera, so I guess it really depends on where you purchase your camera.