How do I get all the police cars in nfs undercover with a mod?

Anyone know any mods that are legit and reliable for nfs undercover where I can download a mod where I can own all the police unit cars inside my garage? I just don't want to go to some sketchy website and download something and end up getting a virus, so does anyone know a trust worthy mod link for this? 

I tried nfscars.net because it seemed legit and I've seen many others use this before, but when I downloaded the files, it said to unzip one of the folders, which I did, but I wasn't quite too sure of what to do next. So can someone help me with this or send a reliable mod for getting nfs undercover police units with instructions?