I actually manage 4 dealerships. We sell all imports. Only the popular tuner cars have high amp alternators for them. Also domestic trucks that use snow plows etc have them available. I bought a Nissan Frontier. I guess that there is just not enough demand. If it is not the truck crowd that demands them it is only the people who put ultra high amp stereo's that need them. Also check out Green Machine. They make great high amp products for many high demand models. Their products will produce almost twice the amos with the same HP draw.
Larry