What I did was soldered a 9005 connector to the end of the solenoid wires and just plugged them in. Worked fine for me. This second time around, I'm keeping the stock high beam while also using the solenoid for the bixenon feature. So splice the black solenoid wire with the black wire on the car, and the red wire with the whatever the positive wire color is on the car. I would advise against using the pigtails they send to splice into the high beam wires. They are crap and the first time or two you plug/unplug them, they will come apart. Mine did anyway.