nj_driver 
2012 Nissan Altima Sedan 3.5 SR 4dr Sedan (3.5L 6cyl CVT)
Great car, but strange noise at 30 MPH
 I've driven 6K miles in my 2012 Altima 3.5.Overall, the car has good acceleration, and is very responsive.The only odd concern is that at 30 MPH (the first time I drive it each day), there is a clunk. It sounds like I ran over a rock and it hit the undercarriage. I returned to Nissan 2 times to have it checked, and was told that it is the ABS Actuator, and the sound is 'normal'.I find it hard to believe the engineers at Nissan would allow this.Check this if you test drive an Altima.