Definitely needs instructions how to install because there is a lot of uncertainties when assembling When installing you don't know how much to cut old tips and where to install new hanger that is supplied. The fitment is okay but it could be better because I had to do a lot of cutting in to my new defuser and all the plastic undertray and the hardware supplied is not the best bolts stripped and snapped very easily because I had to do a lot of alignment work so I had to tighten it many times