but this is different... the MP3 is an official car designation by Mazda... and is named after the MP3 sound file format... Motion Pictures Expert Group Layer 3 audio
MP5 is a submachine gun and the name is not used on any car I know of... using "MP5" will make the person touting the name sound like he's a macho wannabie to some people, and to others sound like an MP3 wannabie because he couldn't get one but want to be part of the crowd... calling "MP5" because it "means Mazda Protege 5" is inexcusable and does not pass that logic test simply because MP3 does NOT mean "mazda protege 3"