Gas Price Spike Relief Act of 2005 - Amends the Internal Revenue Code to allow a 4.3 cents per gallon reduction in the rate of excise tax for gasoline, diesel fuel, special fuels, and certain methanol or ethanol fuels during any period of months in which the motor fuel price index is 10 percent greater than such index for the immediately preceding month (temporary rate reduction period). Allows dealers in such fuels to apply for tax refunds during a temporary rate reduction period.