Beautiful tractor Colby, . . I'd be proud of that one!! Regarding the exhaust,.. yes you should try to keep the rain out,..but check to see if it has a drain hole in the bottom or low part of the exhaust to let rain water, condensation etc out.
My JD-3520-Cab, has the verticle exhaust with the top tip curved over like yours and mine has a hole in the bottom at the first curve for drainage.
If mine did not have a drain,...I would have cut the top curve off the pipe with a hack-saw, then purchased and installed a "rain-cap", (sold for the purpose).
Some folk will simply tell you to hang an old coffee can or similar type can on top of the pipe to keep rain, snow etc out. However, they can become a niusance as when you forget to take it off and it blows sky high when you fire it up,..... and then it comes down and bounces off your nice shiny hood, . . Oh, Ouch!!
Nice machine,...Congratulations and best of luck with it, . . ENJOY!!
. . tug
PS: your dealer made a nice "profit" on this deal,...the least he can do is come out, (or send a mechanic) to come fix that leak!!! It may be minor at the moment but it is going to become a royal pain before long. HE OWES YOU THIS!!! His good, friendly service NOW, in appreciation of the business,..could encourage (OR NOT) you purchasing other implements in future. (Remind him of that.) IMPORTANT: Report the leak as faulty workmanship!! Be certain he records in your file,.. that it "was" reported. IF its not properly installed, it could fall out when you are working and don't notice. You could lose all coolant and overheat,.... NOT good! (Its brand NEW and should be fixed NOW,..and it should NOT be your responsibility, ...(other than pushing for the fix!!!) Good Luck!!