Squeaky Sound on acceleration

[Ag21]

Whenever I accelerate past 45mph and past 60mph it makes this annoying squeaking noise. Can anyone tell me what it could possibly be?

[Akuji]

I've been having the same problem, or so it seems. I hit a steep driveway and it cracked open my downpipe so anytime I rev it up past about 4k it'll let off a really squeeky whiney sound, I dunno if thats what you're hearing but couldn't hurt to take a look.