There are hardly any mods available for the 2004 Solara as of now, although there are a few developments that will be hitting the aftermarket within the next year. I do think that HID bulbs will work with the projectors, although there won't be too much difference in visibility. As for your moonroof, I think you should take it to Toyota before attempting to fix it yourself, plus the car's new, so it should still be under factory warranty.