I have a 2016 Lexus IS300 AWD. I just had the wheels balanced amd rotated. I am noticing that there is a certain flapping like noise when the car goes over 40mph. I have to take a 400 mile road trip early in the morning and will have to drive back the next day. Is it safe to drive? The car and steering wheel doesn’t shake or anything, it is just the noise. Why haven’t I gone back to the shop you ask? It’s because they close at 6 and gave back the car to me at 5:55pm. By the time I got over 40mph to notice the noise, they were closed. Also they are closed tomorrow due to thanksgiving.
If the wheels aren’t loose and the tire pressure is good, it should be fine. What is most likely going on is that the rear wheels had uneven wear on the tires and now with them up front you hear it more. Vehicle most likely needs an alignment.