The ability to add horn sounds for your car.
You got the standard, that funny french one, the low pitch foghorn and my favourite, La Cucaracha.
This is more or less a joke suggestion since there’s no real game play value unless maybe you just want to add the La Cucaracha horn for every car.
I think if every car had it then it would help decrease road rage, when people get pissed off they slam their horn, if it’s La Cucaracha, bam, situation resolved.
PS
My favourite is actually the foghorn.
)