The requirements of the shell I make are that it has to be strong, doesn't crack/snap upon impacts, must be flexible and long lasting. The reason for these requirements are because the car will be flipping over and landing on it's shell, rolling over multiple times and having impact on the shell from various angles etc..., the car weighs around 15-20kg I believe.

The shell is of 1/5th scale. After making the shell I would only need to drill 4 small holes for the body posts. Making a mould will just result in more money being used and I really only need to make a reliable shell for 'bashing' as we call it in the rc hobby. Using a few layers of the fabrics you mentioned will make my costs go up quite a bit as those fabrics aren't cheap and I have to take in to consideration the cost of other things such as resin, gloves, gel coat etc... I'll look in to getting a roller also.