I fitted a steel sheet to my car to slow down anyone trying to steal the cats. Pretty easy to do. I used some self drilling screws and rivets (not pictured).





I know that some people will see this and say that they will still be able to steal it, which is partially true. But where I live, it tends to go down like in this video:

Note that the first guy takes an initial look, he is looking to see if this poor Prius has its OEM cat, and if there are any protection devices fitted. If either of those things are not ideal, they will drive off and do another car - in broad daylight.

If anyone was considering something like this, its quite easy to do, I used a drill, jigsaw, punch, hammer, and a block of wood to bend the sheet.

 

Here's how it goes down where I live https://www.local10.com/news/local/2...st-miami-dade/

 

If that happened in my place 😆 😂 😆 😂 😆 😂 😆

 

Pff, wasting bullets...

https://www.lawofficer.com/thief-cru...tic-converter/

Just because something looks cute, doesn't mean that it won't uhh... bite.

Anyways, on topic - there are ways to mount this without drilling the chassis. I certainly wouldn't want to mess with my underbody chassis rails in any way.

 

It would be nice, but I couldn't think of a reasonable way to do it.

A few small holes in the chassis rails isn't going to hurt it, there are already holes in them for other reasons and the plate provides some additional rigidty anyway.

There are OEM or OEM-approve things that are mounted in a similar way, certainly lots of performance upgrade chassis rigidity type things are fitted by drilling holes in the rails.

 

or you could always protect your cat like this-

 

Nope, the chassis braces use existing mounting points. 3GS included.