Downloaded Vehicles will NOT load

I have tried everything, video tutorials, and threads. No what vehicle(s) I download they will not spawn in the game. I have renamed the files, copied into OpenIV. I have followed all readme files for the vehicles although some of them do not come with instructions or if they do it is a quick; copy ELS files into default pack folder and the vehicle files into latest patchday. Very limited information. Even though I have followed the best I can the vehicles do not replace the default vehicle. If I go into my OpenIV and look at the texture files etc after I copy them it shows the vehicle I downloaded but I can not get them to actually appear in the game. I don't know what else to do or what files to attach to this but I will do my best to send requested info. I'd very much like to get this working. Thanks for any help you can provide.