Putting on my user hat for a moment, I would take each question / answer in isolation (i.e., don't imply intent based on previous contributions). I think that links to one's own site are totally legitimate in well-written content. For example, an answer that looked something like:
"I have encountered a problem like you describe in above-question. As I said over here[link to my totallyAwesomeSiteD00D]:
Quote of relevant content, edited for brevity, including some choice bits indicating
why it was selected.
In your specific situation, I would recommend doing specific-thing instead of what I originally suggested because of some-good-reason. Words words words."
In contrast, a one-liner that looks like this is going to get a down-vote from me:
Try this: [link].
unless that link is solid gold. Even then, I'm going to comment on the answer to say something like "hey, this could be a good answer - please make a bit more of an effort so I can up-vote it."
In terms of this specific situation, their site looks an awful lot like an attempted clone of the stackexchange format with a few cuts and pastes of other people's content. Unless they pick up a lot more useful material, harvesting a bit of our modest traffic isn't really going to do them any good in the long run.
EDIT to add a bit of follow-up: I'm seeing this site show up a lot "www dot automotix dot net" in what are clearly spam answers. I'm now actively interested in tuning the spam filter to start assuming that any content with a link to that site is automatically assumed to be spam.
Admittedly, this has been a pretty annoying day. But still!