Loose engine or transmission mounting bolts?

[Anker]

My newly acquired 2004 Boxter S has a sharp rattle when one of the wheels goes over a severe bump. Rocking the car doesn't cause the rattle, but it only happens when the car is driving at constant speed and I hit a bump or pot hole.

If the car is accelerating moderately or hard no rattle, even when going over bumps or pot holes.

A mechanic friend of mine is convinced that the problem is a loose mounting bolt on the engine or transmission mounts.

Make sense?

Thanks/Anker