The rear torque arm from Speedtech. Another nice piece! No intrusion into the floor, full 3 link style articulation, fully adjustable, and pretty much a no-modification straightforward install. tons of room for 3 inch exhaust too!
We made our own subframe connectors that do not intrude into the interior, weld in, low pro, and bolt to the subframe with 8 bolts per side. you can see the connection to the subframe here.
The entire underside of the car has been treated with Lizard Skin Cermaic insulation, and Sound Control on the inside.