Motor Mount. Torque Arm.
A part that locates and supports the engine. It also reduces vibrations from the engine.

TORQUE ARM

Fits C30, C70, S40, V50

Engine Mount
A broken or worn engine mount will often cause your 2008 Volvo S40 to lurch when shifting gears, and you may also hear a clunk when accelerating or braking. Another likely symptom is excessive vibration from your engine.