I'm going to preface this by saying I have not read though all the pages, and I don't even know if I might have commented pages ago, but to those talking about crimp connectors and soldering: I agree, crimp connectors can be just fine crimped by someone that knows what they are doing, I agree soldering is better, but in some situations it's impractical IMO, whether it be for time or location of the crimp. Obviously a poor crimp is destine to fail sooner or later, but more important than a good crimp vs soldered is shrink wrapping. You have no idea how many times I've troubleshooted a electrical issue, to find whatever repair was not sealed from moisture and corrosion occurred, sometimes if I'm lucky it's just cutting off the end of the wire and installing another connector, other times it's replacing the effected wire. Shrink wrap can be shrinked with an open flame, but a heat gun is better and more even. If the repair is some place shrink wrap is impractical then a few coats of liquid electrical tape will work as it will adhere itself to the wiring. Terminals such as a spade terminal should get a dab of dielectric grease put on it before before it is plugged into whatever it's getting plugged into. When a bulb is changed a dab of dielectric grease will keep your sockets lubed, and moisture out.
We wouldn't see near as much electrical work and re-work if more attention was paid to sealing connections and lubricating connections, both at the factory and by those of us working on them.
Bulk connectors and shrink wrap is what we keep in stock at the shop.