Sabre attic vents

[Old car]

I saw a picture posted by Oakman recently showing the location of attic vents and black/gray tank vents on his Silverback roof. This leads me to a couple of questions.

I have a 2015 Sabre 33CKTS-6 and was cleaning the roof this past weekend. I have two vents that are for the black and gray holding tanks. I have two gray tanks but only 1 vent so I assume they are vented together. Is that a safe assumption? I do not have any attic vents similar to Oakman's picture. What I did notice is behind the rear air conditioning unit, I can tell there is a hole cut through the roof decking but it is covered by the rubber roof material. The hole is about the size of a soft drink can. I did not notice if this same condition exists behind the forward a/c unit but will get back up to check. Should I have attic vents or could it be vented in a different fashion?

[TURBS]

No attic vents.
I do believe the two gray tanks are vented together.
Mine was.

[SilhouettePenny]

I found the same 3 inch hole on my Silhouette RKDS last year (2014 model) located about two feet forward of the shower skylight. Install, or have the dealer install a 5 inch vent so you don't step on that area & puncture the roof membrane.

[MillerTime]

On my 2015 36qbok, I have 2 attic vents and 3 tank vents on the roof and one on my rear wall. (5 tanks total) I believe my kitchen tank is not vented normally but a self-venting one since its in a bar, plus the slow way that it drains.
I would venture a guess that the attic vents were forgot after they installed the roof. My rear tank had the vent stuck into the bunkhouse because they forgot to drill the hole and run it out the rear wall. (And yes it started stinking after a month).
If there is nothing under the membrane, i would definitely get the vents installed. Thats going to be a huge water leak eventually.