Q: Rattling from behind wheel well of front passenger that gets worse with speed as well as a thumping from front passenger tire

Thumping noise like that you are describing can be due to a tire defect, for example a flat spot on the tire. If you have that particular defect though, that usually means the strut is bad. Rattling noises at idle, when the car is not moving, originate in the engine, the transmission (torque converter runs even at idle), and/or the accessory drives. If the sound occurs when the car is stationary, if the sound is not really obvious (pinpointed) on the mechanic’s initial inspection, a quick diagnostic can be performed by simply taking all of the belt driven accessories out of the picture by disconnecting the drive belts and then very briefly running the engine. If the sound disappears, the faulty component is then isolated amongst the accessories and pulleys. If the sounds does not disappear, that means the noise originates within the engine and/or transmission. If the thumping sound occurs only once the car is moving, remote wireless microphones can be used to identify the wheel position that the noise originates from and at which there could be a tire issue. If you want these steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a vehicle noise diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.