Just buy replacemnet pigtail wire connectors and get he trigger for the relays at the old headlight connector, don't have to splice/cut the factory stuff if you want to swap back. Add the heavy guage fused from the starter relay and you'll be good to go. You can swap back to factory in 10 minutes if necessary.

Tom

I use crimps all the time along with shrink-wrap and no solder and I've never had to re do one. Shrink wrap along with some dielectric grease in the connector will last longer than the car. You have to use the tools properly to get a solid connection.