My safety harness broke when he lunged while being tied to a stake in the ground. So not safe for the car!! now I am wondering if these things are any good at all?

He weighs in at 65 Kg's so I need something in case of an accident. A car crate or barrier wont fit in my dinky car either...

What does everyone else use for giant breeds?

i have bernese, and i sometimes use a car harnese. The one i have is made of the same material as a seat belt with padding down the middle that goes down the dogs chest and it is very well made. My dogs love wearing it. I bought it years ago from the internet. :)