They are all designed to dump the water onto the roof like that, and which corner it runs to depends on how the rig is parked. The idea is that the roof is supposed to be waterproof, and condensate will have a chance to evaporate before running off in an out-of-the-way place.
Where would you like it to drain off to? if the front right is inconvenient, park the rig so that the back left is the low spot. It's gotta go somewhere, but I've never heard of anyone attempting to add a condensate line. Sounds like a lot of work to me.