sound generator

I saw a video on the roadster thread here (forgot who posted sorry) and it was moving slowly (the red one) and it appears it was making a sound. Like a “swishing” sound. It could’ve been a semi or something off camera creating the sound but idk. If anyone knows what I’m talking about, feel...

I've driven a Volt since 2011 and just recently switched to an 85D. The Volt had this handy pedestrian horn which the Model S is missing. Wouldn't it be cool to just add some sort of small speaker in the frunk which makes a futuristic engine sound based on the speed of the car ? I just watched...