We use these connectors that are filled with solder and glue filled heatshrink, just use a heat gun and it solders and heat shrinks in 1 go. We have these specifically for PE's inside a saw unit which is subjected to constant vibration, saw shavings and coolant. It been years since we have had an issue with them.
On another note. I'm guessing you sponser a certain big green GQ at tuff trucks???