totally agree - i'm all for people not having it done 
its rarely the product that gives bad results though - 95% of the finish is down to prep..
^^^^very true, same with any detailing procedure,if the prep isnt done the finish will be sh!te.
you will have to polish/seal/wax the car again as it will not stay shiney for long,as with all sealants there not designed for super glossy finishes there designed to protect the paint, a good quality wax will give you the glossy shine and will add more protection if done on a regular basis