I have a C 400 GT, not a CE-04, but for what it's worth -- if it's worth anything at all -- I added a Shad 59X to my scoot, and have been
extremely pleased with it.
1) I'm with
@pedalmike. My feeling is that you can never be too rich, too good-looking, or have too much room in a top case (which is the only one of those three that I could do anything about).
I replaced the stock BMW case -- it was 30 liters when I bought my scoot, although they've increased it to 40-something for model-year '25 on the C 400 -- with the Shad, after using the former for about two years.
The Shad 59X (same thing as the 58X, except for the cover plate) goes from 42 liters to 58 liters, with an intermediate size in between.
I almost always ride with the case in its smallest position, but raise it up for doctor appointments and suchlike, if I want to store my jacket, for instance. I also raise it up when my wife is riding, we stop for lunch, etc., and I put her helmet and maybe one of the jackets in there. Of course, I carry a bunch of personal items, too, and gatorade, etc.
2) I got the Shad from Motostorm in Italy (I'm in NY state, USA), for about half the price that Shad USA wanted.
3) I used the BMW rack to support it, because I already had the rack, because I think it's much more robust than the one Shad offers, and because I didn't have any info regarding whether using the Shad rack encroached on passenger room.
If anyone's still interested, I wrote a long post detailing all this about a year ago:
https://www.bmw-scooters.com/thread...a-passenger-mounted-on-bmw-luggage-rack.3221/ . That thread has assorted pics, and of course more can be found in my C 400 gallery, starting with this particular image and caption:
https://billanddot.com/C400GT/#S-118 .
4) Of course, aesthetics are a personal thing, but I think it looks fine. Others may disagree.
Good luck to all.