[Prius2018]

My 2018 has a slight rattling sound coming out of front driver's side when going over bumps, What could be the cause? the car is great otherwise.

 

[Easy Rider]

My 2018 has a slight rattling sound coming out of front driver's side when going over bumps, What could be the cause? the car is great otherwise.

Could be a LOT of things.
Speculating in a forum like this is pretty much a waste of time.
Have a shop take a test ride with you and then inspect it.

The possibilities range from a loose exhaust hanger bolt to a wheel about ready to fall off.