Dec 23rd 2009 9:20AM One large probelm here... an emergency kit in the truck or in your checked luggage is probably going to be useless when you realy need it.
For car trips, put everything you can manage in the truck - especially hard case luggage. You don't need anything more flying around during an accident than absolutely necessary. Put your emergency kit in a soft bag on the floor behind the passenger seat if possible. If travelling in the colder climes be sure you have extra warm things with you inside the car.
For air travel, you are obviously limited by current safety rules. However, with careful packing and clever shopping, you can make up quite a nice little kit for your carry-on without creating dificulties.
Remember, it can't help you if you can't get to it!