Hey i have a g35 coupe every time i get passed 55mph makes a noise on driver side like if it were metal with metal scrapping together and i really dont know what it is any help!!!!!

 

Maybe your rear brake is dragging or something. See a professional mechanic.

 

maybe a splash guard dragging the ground? i don't usually hear new noises at high speed because there's so much wind noise or road noise. but one that does show up like that is if you have a loose splash guard. it doesn't hang down until you hit high enough speed and then it drags the ground and sounds like scraping. it's like this on my sedan but i assume the coupe has something like this too. it may not be obvious as the thing goes back to it's normal position when you stop. easy to check for by sticking your head under there and looking for sanded down edges of your splash guard pieces or front part of fender liner that meets the splash guard.