I have a ceramic coated T Cross that was done through the dealer three years ago; it has been very successful and made cleaning a breeze. I acknowledge that you may pay more through the dealer but, it is then covered by the dealer on the same terms as the vehicle 5 year warranty. I haven't tested the warranty although I had a dealer fitted dash cam that has played up and the dealer has had that rectified under warranty three years into the car's life. Having said that most reputable operators will offer a two year warranty, but it may be subject to inspection unlike the dealer option. Cheers-John