Lots of emotion on this topic so I'll put in my two cents worth and shut up. USB connectors are not made for high vibration environments with the USB Type B Mini being the worst. We sell USB cables for powering Garmin Nuvi GPS from a generic USB power port. I have to say that they are our biggest warranty issue. This in spite of the fact that we had our tooling changed to extend the rubber as far over the metal shell as the USB spec would allow and increased the Shore hardness of the rubber as much as possible without affecting the functionality of the strain relief. But, it's what we have to work with so we carry on. The USB Type A connector (the big end that plugs into the power port, computer, etc.) is much more robust. We have never had a failure on that end of the cable or with our USB power ports. But then again it is much larger with lots more contact area and support surface. Dielectric grease is a better choice than Vaseline for keeping contacts clean. You don't need thick, you need a thin film for corrosion protection. Vaseline is hydrocarbon based while dielectric grease is silicone based. Hydrocarbons have adverse affects on some materials where silicone is neutral to just about everything.