2000 Infiniti I30 Noise At The Back While Going 70+mph?

[Good Deal A]

I Have Infiniti I30 2000, When I Accelerate Beyond 70mph, I Can Really Hear A Sound Coming From The Rear Part Of The Vehicle. When The Speed Drops Down To 40's, The Sound Goes Down, But Still There Is Smth Heard. I Ve Got Two Quick Trail All Season Tires At The Back And Two Summer Tires In The Front. The Traction In The Front And The Rear Tires Is Different. The Steering Wheel Is A Little Shaky But Not Significantly. What Can It Be?: 1. Alignment? 2. Tires No Good? 3. Problems With The Rear Axle?4. Rear Wheel Bearings Need To Be Replaced? I Am Not A Mechanic, But I Would Like To Know What The Most Common Issue With These Cars Is. Pls Let Me Know, Thank You And Happy New Year!

 

[bossbrakes]

Tire mismatches can cause some issues. Inspect the tires to make sure that the "belts" have not shifted. To do that take the rear tires off and roll them on the ground while looking at the sidewall and the profile for unevenness.
Alignment will not cause weird actions like vibration in general..
The axle is just a piece of steel with bearings on it but the issue could be related to bushings that hold the axle in place...
Rear wheel bearing is a potential problem, for that lift the car up and move the tire side to side and up and down while installed on the car.