I made a template of the male connector on my seatbelt and took it to the local auto salvage. They matched it and and sold me 2 connectors for $30 which I insert when I don't want to wear seatbelt. The important thing is that the width is the same. The height can be a little different.

 

I can appreciate the ingenuity of such an arrangement. The problem I see is that you are also disabling the pretensioner system on the seatbelt when you do this. The pretensioner is an explosive charge similar to an air bag charge that draws the seatbelt tighter so that when the actual airbag does go off it doesn't compress your chest and stop your heart from beating. I think you would be better off at the dealer where you can sign a waiver that says you wanted the alert turned off. That way loved ones and insurance companies don't have to fight over who put the substitue buckles in the latches after the crash.

 

in todays sue evryone society a dealer would be stupid, paper or not for doing this. We just had an advisor and tech get their assses chewed out for turning them off on 2 cars, and made the customer bring them back in. If you do it thats your business, but not us or Jag. Parsonally, I feel pretty naked without mine on