Best car crate?

I have a 3yr old husky mix, last vet visit he was 47lbs and he may weigh 50lbs now but not much more. He does AWFUL in the car. He’s very reactive to anything outside the car. I have a seatbelt and harness for him and he pulls so hard he has gotten out of the seat belt and the harness. I’ve tried a hammock in the back and he just chewed right through it. I don’t crate him in general, but I feel that a crate in the car may be my best bet so I can start getting him out on trails and things more, and also that he and I are safe because half the time I’m holding him by the harness while driving with one hand. He also nips at me when I try to keep him in one place/not hitting the gear shifter/not getting out of his harness.

My stipulation is I currently drive a VW Jetta (4 door sedan) and have no idea what would fit. I would want a plastic/metal crate and not a collapsable one because he would probably just chew through it. I plan on measuring my back seat and looking around (and I plan on hopefully getting an SUV soon) but any ideas on what could fit?? I also have no idea how to get him more comfortable in the car, he’s already anxious in general and he’s fine until we start moving. I don’t really have anyone else to help me train him in the car.