California does have an octane disability problem- the best we can do at normal pumps is 91 octane.
However- Union 76 stations in some areas have been carrying race gas, and the trend appears to be acclerating. In the SF bay area, for example, there are several stations that I know of that do this, one of which in San Jose actually dispenses race gas from the pumps, and others of which will sell it to you from drums or in containers. A bit of a hassle, yes, but at least it's becoming easier than fueling at a track. (One of my prior vehicles needed a minimum of 93 to be happy, or it would substantially retard the timing and get sluggish on me)
And let me add another data point to the "high octane is better in any car" debate- in a relatively low compression car under normal operating conditions, going to higher octane will actually LOWER your fuel mileage without offering any performance gain at all. High octane does not imply more energy in the fuel, just more resistance to igniting, and if the engine isn't designed for that, it's actually suboptimal. (As far as our Elises, I don't have any experience with that engine, and am inclined to think that higher-than-the-minimum-specified octane will be helpful, but I don't agree with prior comments that higher octane is _always_ helpful)
-Knute