I run my connection through the point that the fog lights install if your car didn't come equipped. take off the drivers front wheel and the splash guard their should be a 9/16th inch hole drill through their
I have two spots drilled in the firewall. The first one is just to the right of the gas pedal(you have to be careful, cause there are two brake lines on the other side, tape your bit to keep it from going too far)
The other one was behind the glove box, just above the blower motor case, you will need to cut a bit of the padding back to gain access, but it's a nice clean spot on both sides.