this might sound stupid, but are boxster exhaust systems rigidly mounted

[particlewave]

The engine and trans are mounted on flexible rubber mounts (same as any car). The exhaust is mounted to the the engine and transmission, not the chassis or body. The engine/trans/exhaust all move together.

Droning is caused by lack of cross pipe between the two engine exhaust banks. Stock mufflers and some aftermarket have cross pipes or phase chambers where exhaust gasses from the two banks are mixed so that the opposing sound waves phase each other out and prevent droning.

[madmac]

it wasn't the creation of the droning i was thinking about, but the transmitting of the droning into the cabin for lack of isolation mounts.
but i get you, motor, tranny and exhaust are commonly mounted on a machinery raft like a ship component.
while were at it, what is the point of the aluminum triangular loop at the rear of the transmission? it would seem like a mount / support but mine isn't connected to the transmission. is a bracket missing?

[thstone]

Originally Posted by particlewave

The exhaust is mounted to the the engine and transmission, not the chassis or body. The engine/trans/exhaust all move together.

^^^ What he said. ^^^

The entire system (engine/trans/exhaust) is mounted to the chassis at only three points: front engine mount (rubber isolation) and two rear transmission mounts (high viscosity fluid) to reduce NVH. Thus, the drone isn't likely coming thru the mounts, its just acoustic sound that is transmitted through the whole car. Do a search on exhaust drone and you'll find lots of posts about what others have done to reduce or eliminate it.