I've added it to mine. Seems to be working well. It's really just a far thicker fluid, so it probably still leaks, but much slower. The stuff pours slower than molasses. I'd suggest heating up the bottle first with a heat gun or something.

I can't really remember for sure, but I think on really cold days the steering can be a little stiffer, but its not bad. I've had it in my car for 3+ years and I've only used one bottle.