Hi Julie, use a quality product and proper cloths and it is not a problem, I have never scratched any cars I have used it on and use microfiber cloths. I have used it on a really dirty car but it clogs the cloth up but still no scratches, give the car a wash then use product, then clean it regularly with water less product, use it everywhere but the front windshield you won't go wrong.
Andy
Hi again Julie, I meant I have an Xj too, it is kept outside all year, I clean it with water less wash and wax, it comes up a treat and the more you use it the more protection you have, it takes around 20 minutes to do the whole car. I bought it through ideal world but it is available at most outlets.
all the best, Andy