Silver is kind of a hard color to bring depth to. You can add to the shine however. There are a myriad of sealants and waxes to use. I would try Meguiar's NXT 2.0 for fun. It is priced right, leaves an unbelievable shine and should highlight your paint.
Another option is to use PS21, which is a show car type wax. It might just do the trick on that elegant silver paint.
