SCons doesn't do anything that fancy, but if you did install from the autopackage as root, then perhaps checking out from SVN and doing scons install would fill in the rest for you. It might also just reinstall everything, which at that point you might as well have just checked out from SVN and installed in the first place.
The ideal way to add cars would be to let the user download them one at a time in the game. Maybe sometime in the far future we'll have such a system that lets players browse cars and download the ones they're interested in.
Here's the sf.net stats page for VDrift if you're wondering how many downloads per day etc.:
http://sourceforge.net/project/stats/?gr...ugn=vdrift
I'm sure when we do a new release a torrent of the full Linux Windows and Mac versions could be sustained reasonably for a while, maybe even a few weeks. I'll set up a seed, if someone else will work on getting it into trackers, and tell me how to set it up