They help, but don't prevent burns. My daughter still burned her leg. Probably not as bad with out them. The problem with my shields, the clamp towards the rear is right where you step out of the car. It transfers all the heat right to the shield.
I bought my car with them on. I had one break and was going to leave them off, but the coating is all messed up under the clamps.
The best thing is to stand up and step out when getting out, and put both feet in the car and slide down into the seat when getting in.
Scott
