ABYC standards:
(E-11.16.3.7), “Solder shall not be the sole means of mechanical connection in any circuit”.
"Solderless crimp on connectors shall be attached with the type of crimping tools designed for the connector used, and that will produce a connection meeting the requirements of E-11.16.3.3.” 11.16.3.8."
The reason why crimping is by far the superior method of making a good electrical connection is that a properly compressed connection (that means, the right tool, for the right size connector and the right pressure applied to the crimp) will make the wires & connector pretty much become one. Some people refer to this as a "cold weld"
This is what a proper crimp looks like if you cut it in half
http://www.aeroelectric.com/articles/CrimpTools/GL.jpg
Note that there are no voids in the wire grip area for either terminal. If I had a better polishing tool, you would be able to see individual strands captured in the terminal wire grip barrel. The 500 microinch or so thickness of tin plating on each strand would be visible as squashed ovals traced in the copper surface. As you can see, the wires & connector become one. It eliminates all voids between wires, thus keeping any air out. This prevents corrosion, which is the #1 problem in electrical connections. Corrosion increases the resistance of the connection, which obviously is BAD.
Check out this article "This is NOT a crimper"...good information
http://www.terminaltown.com/Pages/Page7.html
This one also has a lot of good information.
http://www.aeroelectric.com/articles...rimptools.html
While soldering does "seal" most of the connection area, mechanically, it is a fairly weak connection, especially with all the vibrations of a car, which add to crimping being better. Another real problem with soldering and why the ABYC code recommends crimping over it is that in the case of a circuit or wire with high electrical loads, the solder can often heat up enough to soften... combine that with wires that are vibrating... you can get a loose hot live wire inside a car... that's bad. A crimped connection, done properly, isn't ever going to come apart.
i'm surprised your not advocating Lucas Bullet style connectors.
QED