It will vibrate a lot. If your worried about it ruining the comfort of you DD I would steer away from them. It only bothers me occasionally. Every other time I just think "because race car" and I feel better. Haha.
03 Ford SVT Focus - Toms tune, Steeda mounts & stress bar, ORP, 66MM BBK TB, CFM UDP, Rota Grids
The Bad Cat (97 Merc Cougar XR7) - Flowmasters, MSD ignition, K&N intake, 19" Stern ST-4 Warps