I watched the vid - I think all that clatter is the sound of a diesel engine at idle
Actually, I agree - CV Joints. I don't think a little clicking is the end of the world, as long as you are not forcing the wheel hard or applying much power. They are just seeing the limits of their articulation.
Just curious, are the steering limit stops easily adjustible? Maybe limiting available full-lock just a little would help?
For the lowered guys, this might be a good thing to do, since a CV can only articulate so many degrees total. With a lowered car, you've used some of the available angle in the vertical direction, so now have less available for steering at full lock.
Not to get too off topic, but here's a little something from the aircooled offroad world, which might be interesting for you DIY'ers: CV joint clocking. Essentially, if you orient your inner and outer CV joints so the races are "opposite" from each other, they can work togeather to give you a tiny bit more articulation ( I doubt factory assembled axles do this.) I did this on the rear of my VW Thing and was able to get a little extra suspension droop before CV binding.
http://www.outfrontmotorsports.com/cv_assembly.htm