The car is shaking when it is in D gear and the brakes are pressed. Is n gear normal?

It is normal for a car to run a red light, such as D gear, and step on the brakes, because the output power of the engine is transmitted to the wheels through the gearbox, and all the power is digested in the liquid of the gearbox and in the torque converter. At this time, the engine jitter is the same as that of manual brake without stepping on the clutch, which is a manifestation of insufficient power. The difference between automatic gear and manual gear is that automatic gear will not turn off, and manual gear will turn off without stepping on the clutch.

Of course, the engine power cut-off in neutral will not shake because of insufficient power.

So stop for a long time, don't step on the D brake, and put it in neutral or P gear.