To save yourself some money and a little effort (cf is stiff to lay up and wont conform to tight corners) use plain fiberglass underneath. Then use a little pigment to colour the resin black. Ive been told that 'Dulux Ultra Deap Base' pigment from auto shops work well for pigment too, without contaminating the mix.
I know you want to do it the easiest way, but I would think making plugs/female moulds would end up with a better result. Instead of trying to get it right on the first go you have a few chances to rectify minor flaws along the way.
Shape some foam to the rough shape, seal it with paint etc, then get some clay to finish off the desired shape. If bonnet mounted, try to get the shape off the bonnet too maybe. Stay away from tight internal corners as they will not push in without continual force applied (ie bagging).
When dried, wax it with release mould. I use decent quality canuba wax as its a little cheaper. Use small amounts at a time to get really light coats, at least 5. Keep the wax at a decent warm room temp to make it spread easier. Allow a decent time for each coat to dry. For me its I do one coat a night. Make sure this is pefectly smoothe as CF is a bitch to sand. You only want to have to sand the outer dried resin coat (if not using gelcoat) really, really lightly with high grit paper at the end.
Now depending on the shape and whether or not there are undercuts, will determine if you need to use a silicone mould or if a fiberglass one is sufficient. Use a light chopped strand first to conform to the shape. Then maybe heavier to speed up the rest of the lay up. Always get the air bubbles out between each layer.
If skipping the gelcoat stage in the final lay up, maybe get your resin ready in small cups (bigger cups create more heat and will set the pot off quicker) and mix a small batch first. Keep the hardener ready until the last minute. Watch and wait for this to gel a little. Not too much, just enough that it the consitency is not too runny. This will it too stick to the sides of the mould better and not run to the bottom too fast and allow you to get the first layer down to the edges better. Try not stretch it too much as the strands will easily sepperate and look crap. Without bagging it, CF is only used for looks. There will be too much resin in it to give the weight saving advantage. Therefore just use chopped strand of light weave fiberglass for the rest.
I have made a vacuum beg set up with an old fridge compressor that I use to lay up snowboards with 540 gsm triaxial and epoxy resin. I have to get around to welding up my pneumatic press with 6" lay flat hose. Woven glass is nowhere near as strong as dirctional because the strands are woven up and down through each other. When under load it straightens out giving it more stretch and no stiffness. Directional are layed straight in various orientations on top of each other. I use 0, 45, 45 giving strength down the board and torsional twist.
If there are any imperfections left that might give you grief sanding, mix a little resin to touch up, then sand.
