I find it interesting course with plastic sheets always smell 'I found but quite bearable (ie similar to that of a new sports bag that smells a bit after factory) and it evaporates also quickly. Our dog has the trailer already repeatedly used voluntarily as a sleeping cave, so he does not disturb the fine dog nose.
What is important is the way in tush the dog to get used to it (especially dogs who are not accustomed to boxing, swinging suspension bridges can not stand or general problems with it have to lie still). For us has been proven, first time to build the trailer without tires (just times lie in a box), then with tires (in a shaky box are), then carefully pull times (the box moves) and finally on the bike slide (outside something happens and I just sit there and can not).
Conclusion: For the price and the robust trailer there's definitely 5 star. However, if you value specifies that it is easy to Starting and building, must either wait until the material expands by itself or cut the metal bar.