I have the same thing in mine when I am turning slow and tight...like when coming out of a parking space.
I talked to my brother-in-law about this (he builds all sorts of different cars semi-professionally) and he explained that it was the steering rack but that as long as it was limited to the infrequent and extreme conditions that I was experiencing the problem under that it would be okay. In other words, don't worry about it unless you start having the problem on a more frequent basis...like making turns on the street.
Another suggestion as to what might be causing this...you have a lowered car and no off-set A arm bushings...if you get the bushings it will help to fix your suspension geometry and won't put so much strain on the rack. They are pretty cheap in fact they cost more to have them installed than they do to buy them.