You need the correct can bus adapter, check with PAC or Metra. I'm not sure of the actual part number, but they both make adapters for use with factory amps. Just don't expect too much as far as sound quality goes, and they aren't cheap either. IMO, you'd be better off just replacing the factory stuff. I just did mine last weekend, only cost me about $225 for the amp, speakers, and wiring kit and it sounds 100x better! Oh and it looks cool too.
Silver '06 Laredo 3.7L
- 2" RC lift, 1.5" RC Spacers, 58643 MLL's, !Pinch Weld, Spyder Bull Bar, 130w KC Daylighters, Spyder LED Tails, Taillight Guards, Silverstar ZXE's, Interior LEDs, Kenwood 6" DVD/NAV, 12" Audiobahn Sub