You CAN do HIDs in a car without projector lenses, and honestly it will give no more glare than my car and mashow's car, which do have projectors. Check the light beam coming out of the car, and see how much it actually does or doesn't shine up in other drivers' eyes. The potential problem with installing HIDs in a car that did not have them from the factory is that you can get excessive glare for other people heading toward you. People who don't have their lights aimed properly give the rest of us the bad impression.
04-05 STis did not have projectors, but their reflectors inside the headlight housing are a little different. They're called different things to different people, and I've heard them called "squirrel spotters" before even, but housings that come with halogen based lights have specific light reflectors that bounce a small amount of light upward to reflect off of signs and the little reflectors on the side of the road. HIDs are brighter than standard lights, and you will brighten those areas when putting in a brighter light to brighten the ground.
Even a car with projectors, like mine and manshow's will give a little glare above the headlight cutoff. In my wife's MDX, my friend's Cobalt, and my little brother's truck they all have HIDs. I've had them following me, head on to me, really all different positions, and I never have been bothered by the light. I know this is getting wordy, but I seem to be the only person to advocate getting them. Please do some due diligence and make sure your lights are aimed properly when installing them (if you've never adjusted them from the factory then you shouldn't need to unless the car's had an accident).
Point of my rant: Projectors or not, you still have a different light beam pattern than what a car with HIDs will have. I put a different color HIDs in my TSX, and it still had no glare, and the color honestly looked amazing. It's not HID-ish. It IS HID. You'll see very early on that no one will be bothered by it IF they're aimed properly. That's been my experience, and I've had HIDs on lots of cars, and only 2 of them came stock with them. (I tend to go through cars a lot) And +1 for kits from SharpHID.