a shop, drove my car onto a lift and one of the heat shields on my new cats got ripped off. (this is exactly why I refuse to let a shop work on my car, but I didnt have a choice this time). They will pay for a new heat shield or a whole new cat and installation if necesary, but is the heat shield even important. I thought that it helped the cat heat up, by keeping the heat in, but some people have told me that its just to protect the floor of the vehicle from getting too hot and has no other importance. Is it important?