Did you put a sound system in your car?
On one forum they had flash enabled in posts. You could could post Youtube videos like
this, set them to display at 0x0 pixels, and then set them to auto-play. You'd go into a topic and be barraged by GRANDMAAAAAAAAAAAA, J-pop, techno, annoying buzzing noises, etc. all at the same time. You either had to ad-block the autoplay function on youtube or deal with the noise, you couldn't find the video to stop because it was 0x0.