as far as i know shine auto used the original nismo moulds to make these, i'm no expert in this knowledge i'm sure someone else may know more.
They can be bonded on or screwed on i guess either way, my plan was to get them sprayed then bonded on as this would look smoother you don't really want screws showing unless you plan to fill and spray them once they are fitted first
+ genuines !! have you seen the price for them !! you will be dissappointed once you get them why pay 100s when you can have them ready primed, good 2 go for just £60 they are brand new mate !