Noise reduction on 2003 Toyota Echo

I bought this car from a Nissan dealer who said the car is noisy because of poor insulation. It sounds like a small airplane. Noise increases with speed. was considering adding insulation or bedliner paint under the carpet. Transmission was serviced by dealer and seems to shift fine. Anyone have some advise?

1 answer
I would have the tires and/or the wheel bearings checked.
Tires with irregular wear and/or worn/damaged wheel bearings will be very noisy...and that noise will increase with speed.