Splicing the antenna wire

I wouldn't recommend it considering it's going to be exposed to the weather and water will get inside the connection unless you can figure out a way of waterproofing it

 

Silicone it with about 1/4" thickness of silicone. It will look like crap, but it won't get wet. (you'll want to wear a latex or similar glove)

 

Or marine grade shrink tube with the glue inside

 

Either some 3M Scotch Type 70 tape, overlapped to one-half the tape's width, or some Fibreglas° "raincoat tape" that sticks only to itself, will make a jacket for the connectors that will peel off with just a single razor cut when it's time to remove it all.

The Scotch is around $65 per roll; raincoat tape is about $10-12 per roll. However, I agree that for such a short period of time you need it to last for, just a glob of gorilla snot (silicone caulk, rubber cement, etc.) should be way cheaper and work just as well.
73

 

why bother buy some astatic aftermarket co-ax route it independent... run it till you jump out the truck in a year.....