Good dealer for mail order parts?

[tmorales]

I am looking for a sun visor for a '98 E Class with the integrated garage door opener. Mercedes Shop and several other Mercedes parts vendors have told me that the visor is a dealer only part. Having owned BMWs for many years, I know of several dealers that sell parts via internet or phone at up to 40% off the price of my local dealers. Are there any such Mercedes dealers? Thanks.