This is the proper E-Track style of tie down. This is used by all of the major enclosed carriers (Intercity, Horseless Carriage, Reliable, etc)

This is what I used in all of my enclosed trailers for years without an issue. When the E track is through bolted as recommended by the manufacturer (I actually used every 6th bolt hole), the forces in a panic stop will not be a factor, as the car will not move from where it is properly tied down. I tested that theory at 70mph headed south on RT91 where it intersected RT95 when a clueless driver decided that the bird in the road was more important to save than the cars behind her and stopped dead with little notice. I changed my shorts afterwards, but did not have any issues with the 80K car sitting in the back of my trailer.