Slop baby, slop... (It's physics)
Auto's have a nice little torque converter that acts like a big piece of rubber connecting the wheels to the ground. It absorbs the energy that a manual transmission can't.
Thus on a manual transmission, all the energy get's left at the tire, and if it's grip is insuffcient that energy then get's put into the suspension, bushings, anything that will move.
Thus bump..bump..bump.