With the a/c on, the interior fills with a smell that's hard to describe but very annoying--musty rotten eggs, maybe? There also seems to be less cold air than before; I have to have it on Max AC with the fan turned up to make it cool. Yesterday I did a four-hour trip and I'm still feeling a bit dizzy (although if that's related to the smell I don't know). The evaporator drain lines aren't clogged (water drains out onto the ground) so I don't think it's a "mold in the ducts" problem. I replaced the cabin air filter 5000 miles ago, if that's relevant. Last fall the dealer had to add refrigerant but couldn't find a leak. Those are the facts; any idea what the trouble could be? Is this something my local Mobil station can handle, or do I need the dealer?