Check the heat shield.
depends on what car it is and what engine ur running under your hood
its very loud
It sounds like it is overheating. Remove fluff from the fan and vent. Check the heatsink on the processor.
the speedometer beeped so loud as the car speed by
Your car battery could be running low so what you could do is get jumpleeds and get an other and jumpwire it
You'll have to isolate where the noise is coming from before you can do a diagnostic.
Super loud they have be that loud in case a a jerk in front of you is not paying atttenion.
why is it so loud
A NASCAR race car is measured to be about 125-130 decibels. So they are pretty loud. I have been to 5 NASCAR races and the sound doesn't bother me. It is still pretty loud even if you are sitting 20 to 25 rows from the track.