well, 5% does look amazing at it keeps your car very cool, but dont expect to be able to see anything unless its mid day and sunny. honestly, in my pizza delivering days i had a hard time seeing addresses with 20%. it will also take a while to get used to driving with a car that dark. ok try this, put each of your thumbs at the outer edge of your eyebrows, then hold your hands straight out in front of your face. see what i mean? ughh! thats soo annoying! its up to you man, i honestly recommend the 20% or 18%. i went with the 20% to match my factory tint in the rear.