The air dam is spring loaded and many people scrap theirs with out any harm.
It's not 'spring loaded' . The plastic is just flexible . Get under the car and you'll see. I'm not worried about those 3 pieces either, but I'm always careful. The few times I've scraped is minmal, so no damage to the dam. If you hit it badly, it'd get permanently deformed at best. The most important one is the chin spoiler on the GS, and mine is still pristine. Hope to keep it that way .
My drive way isn't steep at all, but I still scrape right at the entrance no matter what angle I take.
I check it out every few weeks and it's still all there and flexes without any issues. I think as long as you move slowly, it should flex without any damage. I've got a spare sitting in my house too, just in case, that the last owner gave me with the car.
Having just replaced mine, I can tell you it is not as easy as some say it is. There is thread over in tech that describes how to. Took me about 90 minutes and a lot of sore muscles, including having to jack up the front end. Might be a whole lot easier on a lift, though. Second time would be easier but still a PITA. Brake pads are much easier.