It is annoying sometimes you download some ISOs and they come in RARs but this is just how it is for now. Nowadays I have a quad-core system that really doesn't take much time to extract even a dual-layer ISO out of maximum compressed RAR set, but I still use this script to burn. You can disable skipping SFV checking, etc, but I would not recommend that as wodim does not care if unrar returns an error. It will burn erroneous data from that point on.
The whole point is that you are piping what unrar gives to stdout to wodim's stdin.
A shell command would be similar to the following: