Screw that!! Grab a hose and make it rain! I actually used a sprinkler to find my leak. (I was too lazy to stand there with a hose forever) With the sprinkler on I could get in the cab and look for the first drip. Start low then re-position the sprinkler higher and higher until you reach the cab.

 

would try that but with our extremely cold weather it would freeze before it found its way now

 

Ever heard of a car wash? Put some quarters in the machine and spray away