box design and port

I am fairly new to anything this big so please bare with me.

To start with my car is a 78 Pontiac Lemans, same trunk space as 78-87 Monte carlo, regal, etc.

Amp is a Hifonics Brutus BXI2608D 850w @4ohm - 1700w @2ohm - 2600w @1ohm rms.

Sub (1 for now) is a RE 18" sx series dvc.

The spec i can find on their site are compact  5.5 @35hz and optimal 8.0@34hz.

Mounting Depth - 9.5"

Mounting Hole Diameter - 16.75"Overall Diameter - 18.5"Bolt Hole Circle - 17.5"Motor Width - 6.5"Motor Depth - 3.25"Basket Depth - 6.25"Displacement - 0.22 cu. ft.Weight - 28 lbs.

Is anyone familiar with these cars trunk design that can help me out?

Also wondering if the port should be up through the rear deck or back, or.....

No one?

Any measurement of the trunk? There specs are done in net. So punch it in on the site slot port calculator. figure about 12 sq.in. of port area per cubic foot. once you figure out the port volume, add that to the net internal, with bracing and driver displacement. That will give you your Gross internal cubic foot. Then you can play around with the enclosure calculator on this site to make sure it will fit.