Crimped connectors, even with adhesives/resins to try to give them some element of mechanical strength, will always be unreliable. Always. I doubt anyone would dispute then, including the manufacturers. Also, you need a crimp type very specific for the type of cable you are doing, and most bullet crimps or scotlok type are wholly unsuitable for multistrand cable, and virtually all loom cables in a car are going to be multistrand for a reason...
Crimps are fast though. Hence the bodgers love them. They rarely last, and cause no end of reliability niggles down the line... ...the type that are a PITA to trace.
I prefer solder and heat shrink. If I'm worried about mechanical strength, you can get heatshrink with a heat activated adhesive on, but I tend to use normal adhesive, and heatshrink when its just going off
Yesterday, I was fault finding an electrical issue on a large ride-on mower. Where was the fault? Yup, a (manufacturer done) crimped connector.