Many drivers who are looking for more power in their car eventually stop looking at mechanical improvements and look at chemical ones.  Modified cars already require higher octane fuels as it explodes at a more consistent rate and the cars can even be tuned to specific levels of octane.  The next step after this is e30, or an ethanol blend.

Using an ethanol blend can provide a significant boost in power but it also requires that each time the driver fills up on gas they add a gallon of ethanol.  The car typically requires a slight mechanical modification to allow for the proper distribution of the ethanol but after this maintaining it is as simple as finding a pump that offers ethanol.