Will I havd a problem mounting my 15lb bottle at a slight forward angle from staright up/down? C5 hatch remember

 

Why would you mount straight up and down? The siphon tube is angled for a reason. The reason is that you are supposed to use bottle brackets, or mount the bottle on the appropriate angle.

 

C5 rear center compartment. I'd like to keep as much usable space as possible. So the bottle could sit at like a 13-18 degree angle from being vertical. If it wouldn't work, I'll just mount it next to the sub box in the corner.

 

I'm doing the 5177 on my Z06. I'm planning to mount the bottle perpendicular to the axles in the rear storage compartment. I'm gonna use the shorter bracket on the front (top of bottle) and taller bracket on the rear (bottom of bottle) and mount them on a 1/4" aluminum plate that will be strapped down to a couple of eye bolts for easy removal. The bottle is tipped up in the front, but still too close to horizontal, so will probably build up the front of the aluminum plate to get the bottle tipped up a little more. Could also do the opposite... taller bracket on bottom of bottle and build up under the back of the aluminum plate to tip it forward.