If you are in a serious accident, a hard sided crate or a specially made car crate in the boot are the safest options. Harnesses can't usually withstand the force of a car accident, unless you buy a serious one that has been tested for it, and I would think those ones would be quite expensive, if they exist at all. Wire crates when damaged can impale the dog.
If all you want is for the dog to be restrained in the car so it doesn't bug you or jump out the window, either will do. I use a harness. If I had a car that I wanted to keep for a while, and I had the money, I would get a proper car crate.
If all you want is for the dog to be restrained in the car so it doesn't bug you or jump out the window, either will do. I use a harness. If I had a car that I wanted to keep for a while, and I had the money, I would get a proper car crate.