I too have heard bad things about newfs and varikennels... namely that they don't allow for enough ventilation, and that the Newfs get too hot in them.
As for crates in our vehicle, we have a Ford Windstar and a Ford Explorer. The Explorer is now our "dog free" car, because we can't get all three in at the same time.
So, we use the Windstar... Cora & Kira both ride in crates, that measure 36"H by 48"L by 24"W. Sailor won't "fit" into a crate, so he rides behind us, and usually helps navigate. I would be more comfortable if he was in a crate, but it's just not possible.
We were in a very serious car accident years ago... Cora was with us. We were traveling down a state highway, going around 55 mph, when a car ran a stop sign and hit us. The car that hit us Geo Metro, which was also going about 55mph. The driver was only 16. He had 3 passengers, a 14 year old boy who lost a kidney, and two 15 year old girls who were riding in the back, without seatbelts. They were both killed instantly.
Neither Russell or I had our seat belts on... I credit airbags with saving our lives. Cora was loose in the back, and was the only one not hurt... physically anyway... she was really nervous for a couple of weeks.
The reason I'm sharing this is that there is a big debate on whether or not dogs are safer crated in a car. Cora wasn't crated, but.... I think we were lucky... I think they're safer in a crate.