Signing an email generates a string that can be used with your public key to verify the contents haven’t been tampered with and that it came from you (assuming that you haven’t leaked the private key).  Encrypting an email is a different process; you’ll need the recipients public key, and they will decrypt with their private key.
The intent of the design of public key cryptography is that the public key can be shared freely without risk.
Look at the 1950 American cars. They’re wild.
One reason for the perception that cars look fancy or not is that you become accustomed to a design when you see it all the time.
Supercars are wildly impractical, and slapping that body on a Corolla chassis would make a Corolla that only seats 2 and has no space for bags, but somehow takes up a lot more space than a Corolla. Also, downforce is bad for fuel efficiency.
Your note at the bottom is interesting. The perceived luxury of a car is not related to the quality of the vehicle. As a car guy with a penchant for German cars, I do have to admit that while they’re wonderful in many ways, a beige Corolla or Civic will stand far more abuse.