Genius...another link which has been posted a few times will also help, especially when it comes to quick info on strut clearances:
http://toy4two.home.mindspring.com/offset.html
On another note, I want to reiterate it was not my intention to demean the efforts of Schatten and Phantom with regards to the FAQ wheel/tire info. Phantom and I are having a lively discussion within the thread whose link he posted just above. My point is that I think it needed to be more detailed with other choices. Granted, going low on the offset while staying close to OEM in both tire/wheel width isn't going to create a 1.0g monster, but for many owners, these are clearly acceptable choices, creating a daily driver that both looks great (depending on one's own .02 I suppose with regards to wheel style) and didn't cost an arm and leg to obtain. The handling won't be adversely affected (providing the parameters stated ad naseum are followed) in all but the most daring circumstances. I believe I did read somewhere that the FAQ had tried to be updated and to date, those additions hadn't reached publication. I could be wrong (afterall, I think I've read about 500 posts this week in this forum....yikes!) but my memory seems to be saying this.
Anyways, I too liked the Kasai's but even with my willingness to deviate from the norm, I cannot recommend them in the 18-inch size.