escape hatch

[petarm1]

good day folks. i am looking at putting 2 roof vents in my bus. i really dont want to cut into the main roof of the bus. has anyone been successful in putting a vent in a escape hatch. they seem hollow and are close to the right side. and if not can some one give me good advice on the way to do a good install. i am planing on getting 2 maxx air turbo vents

[robertglines1]

Good place. And if you would happen to need exscape route it is still  there. 

[petarm1]

i am thinking i should be able to get away with just the max air unit and modifie it to fit the lid.i dont see why i would need the vent as well but i may be wrong. any thoughts