I have been using these to tie down my car (Scion FRS, about 2,750 lbs) to my open car trailer that I installed e-track to the wood floor. The straps have been working great and no issues. The straps stay nice and tight and the car is very secure.
Just make sure that you have enough e-track in the front and rear of your vehicle to clip in the straps and have enough room to work the ratchet without hitting the bumper. Also ensure that you have enough gap between your tire and fender to fit the strap with the rubber blocks over the tire - this shouldn't be an issue unless your car is lowered pretty far.
Overall, I find this method of securing the car to be very secure and better than tying down the frame or using axle straps through the wheels. If you ever look at one of the big car haulers, they tie the cars down in the same manner (over the tire).