In order to run the .package file, you need to make it executable. It's been a while since I've used KDE but you can probably do this with Konqueror by right-clicking and going to properties. Otherwise you could do it on the terminal like this
Code:
chmod 755 vdrift-2006-10-06-full.x86.package
I've just rewritten the Linux installation instructions when I moved them to our new wiki. See if this page doesn't answer your questions:
http://vdrift.net/wiki/index.php/Installing_on_Linux
The tarball you downloaded is something used to create a Debian package. That won't do you any good. The .deb file you downloaded is just the data package - you need to also install a package for vdrift itself. The AutoPackage isn't like this, you only need one file.