I wouldn't bother with an oven cure on body panels. The panels will post-cure in their working environment, and with skinned parts you have plenty of resin on there to cut and polish into once that has taken place.Just skin the bonnet, fit it to the car, and use it for several months (preferably through summer). Once it has seen a good bit of sun and engine bay temps, you'll notice the fibre print through to the surface and you'll get a bit of rippling. It will happen quite quickly if the weather is warm. But once it has been exposed to those conditions a few times, you can then take it off the car again, flat the surface down with 800 grit, and then move through to 1200>1500>2000>2500>3000, and finally compound to bring it back to a full gloss.
After that, you shouldn't see the print through come back unless it is exposed to a temperature higher than its Tg again. On a 30 degree day, a carbon bonnet can easily see in excess of 80 degrees. So it may never stay completely flat. But in all honesty, in my experience it is that initial shrinkage that is the worst, and after that it doesn't print too badly even if the bonnet gets up to 90-100 degrees. It's not as bad a problem as you might think.