I say if you are going to add side skirts, get a new front bumper as well. Just adding side skirts to me without the lines meeting up with the front bumper looks out of place. That's why they usually sell these parts as "COMPLETE KITS" including the skirts and front bumper together. As for the rear, you already have the diffusers added to your rear bumper so I think it would complete the lines of the car with added side skirts. Make it all an even level.
