Satellite/iPod Install Questions

[Powertwang]

Howdy. I'm considering purchasing one of a few used 209 convertibles (2 500s and one 55, 2005-2006), none of which currently have factory satellite and iPod interfaces installed. The very helpful sales lady at the dealership told me while test-driving one candidate earlier today, that she would strongly caution me against having the satellite package installed because of how invasive a process it is. She didn't go into a bunch of specifics, but I got the impression that she's very concerned that the installation would (or at least could) so significantly disturb the current fit and finish of whatever channels/panels are utilized for the running of this system, that she said she would "never have such an installation done on (her) own car." Is this install really that dangerous? If so, why?
Re: iPod, the sales rep urged me to have the dealership people do the install. I'm a reasonably handy guy and have installed an iPod interface on my '05 BMW and don't want to pay to have something done that I can do myself. I see a lengthy thread about iPod install, so pardon me if the question is totally redundant, but is there any reason - other than convenience, of course - to have the dealer do this instead of doing it myself? Thanks

[CoachPA]

I called my dealership about installing satellite radio in my 05 CLK. They said that it wouldn't be worth the money. It would have to be Sirius and they would have to install a new harness - whatever that is - and the cost would be prohibitive (in the $2K range). I had a 3rd party install an XM Radio with so-so success. There is an aux jack in my glove box that they used. Their main problem was finding a hot switched power source. Finally had to wire directly from the fuse box. The mount they installed didn't hold for very long, but since I don't change stations that often it doesn't bother me too much.

I don't know anything about the IPod interface.