is it even possible to delete 1 rear seat, or do both really have to come out if you're going to get rid of them?

 

Rear seats are in three parts.

One solid piece bottom and a two piece split folding back...

Could find a bottom seat section in the NAM marketplace instead of cutting up yours then mod it into a single side ?

 

what about just removing the seatback only. would that be any issue?

 

No, but you could just leave it down.

 

You can remove just the seat back. I've considered doing it, and covering the seat with a long sub box it would be shaped like a "P" the flat part over the seat, and the bigger part in the boot. I'd make it a ported box so things could still be placed on top without damaging the woofer.

 

It's easy to just remove one of the seat backs and leave the other one in. The two backs do not connect in the center so you will be fine with that.

And that isn't a bad idea seeing as how the majority of the weight in the back seats is from the seat backs themselves.