I've been using Albo1125's way of installing vehicles. You install them the same way every time and don't have to worry about getting them in the correct place. Plus, you can name them what you want and can have unlimited vehicles. There is a small bit of coding you have to do, but he includes the base files and he has videos on how to do it all step by step. The readme is very useful as well.
One thing I noticed, as I'm new to this myself, is that once you spawn the vehicles, you need to wash them. They always spawn dirty.