DerKai2008

Ha ha, no biggie!  Let me explain what the mods folder is.  It's essentially a shell that protects your files.  So if you replace a car in the mods folder, it will not touch your core files, meaning if you deleted the mods folder, you'd still have your game working fine.
 
 
Now, to make a mods folder, open your GTA directory as you would normally, not via OpenIV.  Create a new folder named "mods" - no quotes.
 
in OpenIV, go to update-->x64-->dlcpacks-->patchday19-->dlc-->x64-->levels-->gta 5-->vehicles.
 
Click "edit mode".
 
You should now see a big red box which warns you that you're not using a mods folder.  One of the options it gives you is to create that path in the mods folder, click that.
 
After, you should notice your directory has changed and you're in the mods folder.  From there, do the steps listed in my previous post. 🙂

No problem at all!  Try reading this and see if it helps - http://openiv.com/?p=1132