[John10608]

Well, I'm not going to argue and argue this point, but, I have never seen a center brace for the radio tray in any vehicle let alone a mustang that I drove that I can recall. And yes, I have never seen a plywood tray, not saying there wasn't one, but it was always a fiber partical board.

The braces have one hole in them at each end. If there are 2 ( I'll have to go look ) they are closer together than the ones pictured.

I do know that in the mid 80's ( 84 or 85 I believe ) to about 89 ? we had short wood emt back boards in the trunks. Stuffed behind the spare tire under the radio tray. Placed back there mainly because I don't think they were ever used much at all if ever in the field, probably the reason they only lasted 4 - 5 years. ( I have several of them here ) want one ? LOL

Maybe there was some sort of metal backing they attached inside the spare tire cavity that extended above the trunk floor a few inches to keep the board in place and not sliding around.

That is the ONLY thing I can think of. There just was no center brace in the mustangs. I can not think of anything else the CHP would attach in the spare tire cavity. Maybe they made their own brace to hold the jack and lug wrench, attached it inside and bent it over the top of the tire ? Then how would you get the tire out ? Doubt it.

I do know it was a B &%# H to get the tire out if you had a flat.
You had to empty the whole trunk practically on the side of the freeway, change the tire, stuff it back in the trunk with the rest of the stuff, then head back to the office to get a new spare which required removing all of the above mentioned C %$# P and put it all back again.
P. I. T. A. ! lol But.......... guess maybe that was why the lazy officers called a tow to fix their flat. I thought that was pretty embarrassing myself.( let alone lazy )
I'd change my own tires.

Besides, why would there be 6 holes spread out like that for one thin 1" verticle brace ?? Wasn't for a brace.

Good luck. I have never seen holes like that before though.
My guess would be something to hold the backboards in place behind the spare.