When I ran light-medium duty flatbed wreckers, I almost always used the JTR hooks like nisaacs pictured. Attaching directly to the frame section was always preferred. I would occaisionally have to use the large J-hooks and go to the solid rear axle and lower A-arms on older vehicles (pre-front wheel drive drek-and older trucks, etc). We NEVER ran straps through or over the wheels or tires. Good Gawd. That's just begging for trouble.
When I'm hauling cars for myself or others on my own car trailer, I use axle straps on all 4 corners.
Sounds just like it should, the axle strap portion (on the left in the picture) wraps around an axle or lower A-arm at the corner of the car (or truck). On a classic or exotic car, it limits the chances of chipping paint or finish on something high end.