The marinco plug does have a cap. It also has a hard plastic case and flange. So, you can only mount it on relatively flat surfaces. That alone limits the possible locations. Now, I want to keep it out of the rain, so it can't angle upwards. However, I can't mount it low as it may get snow/slush in it. I'd also prefer to have it on the front of the car somewhere. The grill isn't a bad idea, but I'd have to make something to mount it to since my whole grill is currently blocked off with coroplast and thats obviously not rigid enough to hold the plug.
