When I bought it, it didn't come with one, got a standard plate made up. But not sure how I attach it to the fins on the bumper.

 

should have 2 metal brackets with holes ready to screw in. i simply used double sided stuff to put mine on where the screws usually go and it havent fallen off yet

 

Didn't think double sided stuff would be good enough, but seems to be the easiest way forward.

 

Decent double sided stuff is strong enough.

My old front plate was held on with it for about 18 month or so, before I changed to a vynyl plate;



My rear plate has been held on for over a year now, using the same stuff;



I used No More Nails double sided sticky tape.