I use a product called Rejex...I don't know if I would have chosen that name for the product, but that's what it's called. LOL. I've used it for a couple of years now.
RejeX®: So Slick, Bugs Can't Stick!
RejeX is actually not a wax, but a thin-film polymer coating. It also is touted as a bug repellant, and works fairly well.
For other discussions of the product, go here:
http://www.m3forum.net/m3forum/showthread.php?t=34430
http://www.bobistheoilguy.com/forums...982044&fpart=1
Here's my car below. For silver, you don't get much more of a shine than this: