Hi Mike, No you would not need to as Carbonin design their bodywork to fit perfectly with the OEM subframe. If you are looking to change your subframe in the future please note that after market subframes do not have all of the original mounting points on them and they often need customization to the subframe or bodywork. See full answer »
You can use the oem seat if you want to, you will need to modify the plate that holds down the oem seat however this is something some of our customers have done in the past. See full answer »