Edit... I mentioned this to Shawn... sorry, we installed topsoil and sod in our front yard today.
He says the subscription won't automatically add you to the Garage at the moment... something he's still working on. Let me know if you did subscribe and we can take care of it.
If you don't mind, try doing it through the forum. I think I've got it all working now. There should be a link in your user settings for "Account Upgrades". Here's a link: http://www.nc4x4.com/forum/index.php?account/upgrades. See if that works.