Non-starter for F83 vert owners as we use the key buttons all the time opening/closing the roof when outside of the car - also 7+mm is really quite thick and although credit card sized clearly will not fit in a wallet i.e. basically this would be a flatter version of the key fob - don't get me wrong , still a cool idea as clearly other manufacturers have gone this route and best of luck indeed in the venture. If you manage at some point to incorporate the buttons then I will look again
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