I'm not sure if you'll even want to answer this, but here goes.
I really dislike the fact that the A/C in my '04 Elantra is coupled to the defroster so that the they always come on together. I've heard a rumor that this is a new federally mandated setup, but frankly, it really sucks if you live in a cold environment and need maximum heat to clear snow and ice from the windshield. On '03 and older cars, it's a simple matter of snipping one signal wire to decouple them, but still be able to turn on the A/C manually with the defroster if you want to.
Unfortunately, he '04 has a different control module that's more difficult to decipher. I've examined the wiring diagrams, but it's hard to relate them to the components. I'm on the verge of opening the control module in the dash to see if I can find where the signal from the mode selector switch connects to the the A/C signal output, so I can sever the connection. Any ideas?