As I had to learn the hard way StuffIt isn’t always capable of uncompressing RAR archives—especially when they are compressed using a newer version of RAR. As a workaround I compiled the latest unrar sources for the command line version on my Mac and bundled them into a nice little package. So, if you’re not afraid of using command line tools, here it is:
As always: No guarantees whatsoever given. If it breaks, kills your drive or trashes your files then you own the parts.
[Update] Although this version is compiled from the 3.5.4 sources, it will report itself as being version 3.51. Seems like someone forgot to update the version information in the source files. I didn’t want to introduce any changes, so I left it at that.