http://www.germanshepherds.com/forum/general-information/138482-canine-seat-belt-choice.html has some great information!
Looks like they have two lines - any quick thoughts about the differences between them - one seems to be a little more expensive than the other.I have this one, it's from the same company as the Champion.
Good quality. Poor service. Stay on them.
SURVIVOR Big Dog Seat Belt System
There are multiple threads on seatbelts for dogs.