Sorry guys but you're wrong .Yes he can put amp on the factory radio . he only needs an HI to LOW level output device like this item STINGER SGN13 HIGH TO LOW LEVEL OUTPUT CONVERTER 35X2 - eBay (item 230575275894 end time Feb-16-11 15:50:09 PST) .The percentage lost in power is less than 10% it's not much . What do you think ,can you make it work like this ,it's so simple