I downloaded a file that is supposed to make AI vehicles driveable, but the sparse instructions don't make sense to me. Has anyone else made this work? The file name is "Ground-Vehicle-Kit-v.1.zip".  I also have never had any luck with any of the other vehicle downloads such as Loopy Larry's Schoolbus (I just get errors and crashes when I try to use it) and the BMW (never shows up in the Aircraft Selection list).

I am familiar with how to implement addon aircraft and helicopters, and have dozens of them from Simviation and other sites and made them work. But never any kind of ground vehicle or boat downloaded from this site (like the nice looking steam boat, which also never appeared in the selection list once installed).

Any help will be appreciated.