On my coach, both AC units have their condensate drains running over the surface of the roof and over the side of the motor home. I always thought this was rather crude for an otherwise higher end diesel pusher...but considering how an internal/hidden drain might fail spectacularly in regards to vehicle water damage perhaps I should count my blessings...
2007 Tour Master T40C
Acura MDX toad
"It takes a great deal of time to recover from any improvement..."