Is trim required between regular diamond plate and .04 alum?

I'm at the stage where I've discovered my first mistake....my profile including bottom rest requiring coverage is 49.5 inches high, which means I need 5 foot wide aluminum if I don't want an overlap and a seam. So I've decided to use diamond plate as a rock guard all long the sides and front bottom. I've read the threads over and over; some suggest using z holding to make the transition, but I'd have to order it. Others suggest glueing the checker plate over top of the .04, which would make me worry about leaks....wouldn't it make more sense to overlap the checker plate with the aluminum sheeting or is it ugly? I've been looking a close ups of pictures on this forum; wondering if anyone can suggest what they've seen/done that turns out waterproof and isn't an ugly transition? Thanks in advance for your advice/replies...
KJ
KJ