To the original poster... this has happened to a few people with 2005's but I had not heard of it with the newer 2007's and 2008's.
It's probably nothing horrible, but not exactly "normal" either.
Do try that tip of braking briskly in a safe place with the car in Neutral.
You can go from D to N at any speed.
Then try braking gently in N back down to zero miles per hour and see how it feels.
If it continues, have a dealer look into it.
It may be ok and a little bit expected from a brand new vehicle.
I would not expect this from a car with 1-2,000 miles.
FYI there is no regenerative braking in Neutral, and there is no regenerative brakes at 5 MPH
and under. The "grip" some people feel is when the car changes from regen ( motor brake ) to brake pads. This change happens at 5 MPH
when you are coasting to a stop. I feel a little harsh "grip" sometimes, especially when my brakes are wet. As soon as they get hot and become dry, they grip harder.
I never have (heard) any sounds.