I guess that I figured the PL-239 connector would be more versatile if I wanted to replace the cheap antenna that I can afford right now with a better one later on. I may also want to set up a larger antenna (read: won't fit on the roof) to use the van as a temporary base station. Would the NMO mount allow me to do that?
You did get the right idea - I am concerned about getting a setup that will be waterproof and not damage the car.
Thanks again - pretty new to the mobile thing.