So far as I am aware, the vehicles in S trim did not receive any lettering whatsoever above the side indicators on the front fenders.
Vehicles in SE and HSE trim were badged as such above that lens. If that's accurate, all you have to do is look for one with no stickers in that area.
I don't think the S models got contrasting piping on the Duragrain seats, and I don't think a two-tone steering wheel was available, either. I don't think the S ever got the armrests, either. Could be wrong, but if I'm not, those are dead giveaways when considered together.
That should help, anyway. If you're just after the Duragrain seats, that's not a reason to pass up a vehicle in great shape. I don't know if sunroofs were optional in 2004, or even available on the S, but if they were and that's why you're after an S... Yeah, that's a different story. I'm struggling to imagine another reason to specifically want an S and potentially have to wait longer than otherwise required to get one in decent shape.
I believe by 2004 they had armrests like the rest of them.
In previous years, SE was the top trim level, such as my 2001; but by 2003 they'd added the "H", for some reason or another. Same trim with an extra letter.
Maybe it just sounded cooler.
Cheers,
Kennith