Well, the lines of the kit might look a little off if you go with the buddy club rear as that rear bumper sits a lot higher than the black widow rear. If you look at your car from the side, the rear bumper might look weird to you as it doesn't sit as low as the rest of your kit.

But if you want the rear of the black widow to look more "uniformed" from the rear, you can cut out that lower center piece of your black widow rear so that it doesn't look like you have two exhaust cutouts.