I have made chassis and custom parts out of Carbon Fibre for my TA04R and Xray as well as for friends cars.
I have made carbon fibre Battery Hold Downs, Top Decks and Chassis, Spur Gear Plates, Transponder mounts etc etc.
I use a router and a high speed carbide bit 3mm round. I make a jig to do each cut I need and mark out the carbon fibre sheet accordingly with a scribe. I drill a pilot hole and set the carbon fibre sheet up on a special work bench with the Jig over the top.
It is a fairly slow process to set up the jig just right but the finish is as good as anything you will buy on the shelf. Only use the best router bit and the best tools and take your time.
There are a few other tricks but it too much to get into here