Horse hockey. My Mercedes will not let you lock the key fob in the car, sometimes if the wife leaves her key and purse in the trunk and I have my key it will not lock. 

Back in the ‘90s I unlocked and got into an ‘89 Mustang Convertible that looked just like mine, same color same interior even had a Ga Tech sticker on the back window. However the ignition key would not start it. That’s when I got out and checked the tag.  Yep,  mine was one row over....  oops.