Anyone able to check over my design?

[Demo250]

Hey guys, putting one 12" Audioque HDC3 in my ext cab truck. Gonna go right behind the drivers seat. The dimensions in the pic are pretty much my max usable dimensions.

At first I was under the impression I would be better off with a slot port. Upon playing around with it, it seems to take up too much valuable volume. I've created a design that should work well (using PVC for ports) Hopefully I can get an experienced designer to take a quick look and see if there are any problems with it? (Only learned everything in the last 3 hours or so; so I very well could be missing something)

Here is the design:

All dimensions are outside dimensions.

Are the 2 ports okay at 19" long? I know there is the slot port rule about how the port must be its own width away from any wall. Not sure if this applies here in any way?

One last question: I was considering flaring the ends of the ports a bit. I remember reading somewhere that a flared port actually has to be longer to maintain the same tuning than if it were just a regular round tube. If this is true, about how much longer in relation to how much flare?

Hopefully I didn't mess up too bad.

Look forward to having an expert opinion so I can build it without worry of having designed something wrong.

Thanks