I just bought Hella Supertones to upgrade the stock horn in my 09 prius. Has anybody installed these on their car? Will the stock wiring be able to handle the amperage of the horn or do I need to "upgrade" wiring on the car. If I need to upgrade the wiring, I need to "tap" a line to the positive terminal of the 12v battery. Does anybody have any advice as to where I could "tap" the + of the 12v battery? Any helpful input is welcome. Thanks.