You'd be better off by using Steam workshop. The mod you downloaded is for a legacy version of Spintires.
I just downloaded spintires from steam several days ago and I've been enjoying the stock trucks and maps but today I decided to download and install my first mod truck. I am a complete noob to the game and especially installing mods so I watched a youtube video on how to do it, followed it step by step (I thought) I created an account with oovee, downloaded the dodge ram 2500 dually, installed those files into the media file (not zipped) and then the game wouldn't even open. I went back into the media file, deleted the files that I had installed and then the game opened but didn't respond fully. Like when I Press the M key for the main menu nothing happened. I closed the game, restarted my computer, tried to reopen the game and again it will not even open. I'm confused and frustrated! What should I do? I really look forward to being able to download and install some trucks and maps! Thanks in advance for any information!
To fix the issue you have now, follow this tutorial to clean your game.