To install and run soccar, you will need some files from the project files page and follow the instructions for your OS below:
On Windows you should grab the installer .exe from the project files page and run it. That's all.
On linux/x86 just grab the most recent soccar-*-linux.tar.bz2 file and also the same soccar-*-data.zip package. Extract them to the same dir. The game should be started using ./soccar.
These requrements apply only to the source distribution. The Windows and Linux binaries should work on any recent OS version. If they don't, bug the author of preferably try building the sources.
Also note that it's not yet easy to build Soccar from source, because I experimented with different things in the libraries I used.
The only slightly problematic part is enet. The include files have very generic names, like time.h and memory.h which caused some problems (name collisions with STL for example) so I changed all references to *.h to enet/*.h both in the headers and sources to make it work. I updated the Makefile to reflect this change, too.
Another smaller problem was that the Makefile in it doesn't provide an install target. Just execute the following code as root to install it:
# install -m 644 include/enet/*.h /usr/local/include/enet
# install libenet.a /usr/local/lib/