The manual is on oople, 870c, but same car except for the body.
http://www.oople.com/rc/manuals/yz870c/
That version doesn't use the top brace, only the angle fibreglass with the belt tensioner mounted off that. It's not much good though, the car flexes enough to lose all belt tension on the front. Also there are no holes for attaching the top deck to the bulkhead caps. You can drill them to mount a top deck but I tried that on mine and they just cracked in the first 5 mins of running.