Many people will be reading this because they are looking for dog crates for Pitbulls which are indeed extremely powerful pooches. You will need a good gorilla-tough dog crate to keep them under control. Physical strength is only one aspect of a dogs escape ability! Pooches are intelligent animals and will work relentlessly to find a weak spot and exploit it.
Experiment with different crate placements. Sometimes, you can reduce your dog’s desire to escape from his kennel by placing it in a different location. You may find, for example, that by placing him within view of a window, he stops trying to escape as much. You may also find that the opposite – eliminating his view of squirrels and pedestrians – may calm him down more.
Update: We traveled quite a bit this holiday season and this portable crate was absolutely awesome! I have seen some reviews about bad zippers but suspect it's due to misuse. You have to raise each side before zipping it -- just common sense, people. Otherwise, there is too much pressure on the zipper. I think zippers on this crate are sturdy. Another suggestion is placing your dog's favorite bed inside. The crate (we have extra large) has plenty of room to add an extra large fluffy dog bed our dog loves. Because the crate folds flat, we place the crate in the cargo area and cover it with dog's bed when on the road. The dog sprawls like a queen! :) When we get to the destination, we unfold the crate, throw the bed inside, and voila -- cozy house that ... full review