Ever since I lowered my car and put bigger wheels w/lower profile tires in the front, I've been getting this strange buzzing sound from somewhere on the underbody of my car at high speeds. It only happens over about 80km and mostly only when i have a passenger. It sounds like plastic on plastic too...
would it be that something came loose underneath and is flapping around from all the wind?
Anyone have any idea what this could be? Thanks...

 

but the wide tires definitely hum around those speeds. Maybe one of the shock boots is causing it, you need to investigate a bit further and get back to us.

 

Does the noise appear when you go over big dips in the road? You might have some clearance problems since it seems to appear when you have a passenger in front. Look at the tire tread and sidewalls for signs of rubbing...

 

yeah, i hear noises when i smoke to much shwag...scary,,

 

No, bumps dont do anything so I know its not my tires/wheels rubbing on anything. I even got spacers for my front wheels just to make sure and its still making the noise. Im gonna get under my car today to see whats going on...

 

well, you said buzzing then you said plastic against plastic...those two things are different sounds. Is it a scraping sound?