I had this bug before this post, but in th engine designer, sometimes the little ! icon will blink and say the engine is knocking even if the knocking % is 0 and its square is green. I think the problem is that it’s not showing the decimal points but still simulating them (eg 0.1 would show up as 0 to the player, but the knock detector would still say the engine was knocking since 0.1 > 0.)
EDIT: New bug discovered!
These fixtures were on a production variant of this car. I load this race variant, and there they are.
Except this time, they’re red.
And they’re on the grille.
EDIT 2: Sound bug discovered! I am on a roll today.