Thanks! While not as sexy as a Goose Gear set up, this plate is extremely functional and has been amazingly useful. We just got back from our Christmas trip to Texas and the plate still makes me smile every time I'm loading up.
I'll get you measurements later; unfortunately, my work notes were on the work piece and are now painted over.
It's a straight rectangular cut, although I did some custom contouring. First I put a 1/4" roundover on the bottom of the sides and back to soften the edges that sit on the plastic. Afterward, I used an RO sander to slightly taper the bottom of the last ~8" toward the rear. The plastic trim bevels very slightly and this prevents putting too much pressure on it. I rounded the top of the back edge as a comfort relief as well. On all the plastic contact areas I used black Gorilla duct tape to protect against scuffing.
I used the factory d-ring mounts behind the seat. There's a metal bracket that bolts to the floorpan and it's near enough to co-planer with the ledge provided by the plastic trim. I did need longer bolts in order to re-use the OEM d-rings and go all the way through the plywood though. I didn't have the OEM nuts in the rear either and needed to use rivnuts. I referenced the rails underneath by the spot welds and put the rivnuts within that saddle for maximum strength.
