Interior: Trunk and safety.

So our trunk is going to look pretty plain. Once all the trim pieces and carpet is in, we're going to make some small additions that hopefully won't ruin the overall look of the interior.

There's a small container behind each seat, I hope to move the battery in there. That way it's out of the way, gives us more room in the engine bay, and moves 30lbs of weight from the front of the car to the back. If this doesn't work out, I'll get a plastic box and mount it in the trunk.

Eventually, this car will see time on a race track. Due to the increased power and speed we will need a roll bar in order to safely be on a track.

This might be a little aggressive, but it gives the correct idea. We also will need to run those harnesses. I'm not sure I trust 40 year old seat belts so some correctly mounted harnesses make sense. The harnesses will depend on our seats.

In order to keep our cabin quiet enough to talk in while flying down the road, we'll have to install some sound  proofing. The factory sound proofing will have to be removed (Dry Ice!). The factory sound proofing was put on before the body was painted so it goes "Bare metal-glue-sound proofing-paint". That means that 40 years later the glue is gone and there's a gap of air and moisture under the factory sound proofing. That means there might be rust. Hopefully we can remove the old sound proofing and not find giant rust holes.

Once the rust is fixed, we lay down a rust encapsulation paint like POR-15, then lay down rolls of Dynomat or some other sound proofing material.

That's about it. If everything goes right, then we'll have a nice 70's interior that's comfy, quiet and has a nice sound system. Perfect for a race track or a 400 mile trip.