Here is What you will get simply bolting on the '04 rims.
Without lowering, you notice the gap more due to the 45 offset on the '04 rims compared to the 50 offset of the '03 rims. Unfortunately I didn't get a pic while I had the rim on the car, but it looked a bit awkward. I will retry the 4 rims for a few days and maybe that will overwhelm my "used to it" bias of the stock rims. but the gap was more noticeable since the wheels protruded more. If you look at the bolt area, you will notice a deeper setting on the wheel on the right ('04 rim) which causes the tread to be more visible when view the car from the side, thus making that gap more noteable.
Let me know and good luck!