Reception Problems on Cape Cod

I recently had my 2008 Toyota Highlander relocated from California to Cape Cod. I had very few problems with reception in LA, however here on the Cape the reception is rather spotty. I called Sirius and they told me that reception is good in all 48 states, blah, blah, blah and referred me to the local Toyota dealer. I went to the dealer here and told him about the problem. He said, 'Oh, yeah, I had the same problem myself and I cancelled my service.' Since then I have heard of several people here confirming that service here is not great.
Does anybody else have this problem?
Is there anything I can do about it?
I loves my Sirius, but if the service sucks here on the Cape, I'm canceling it.

I spend quite a bit of time on the south shore and never have any issues other than the dropouts from trees and powerlines that aren't typically present in the city.

Well, since the Cape is mostly trees it seems to be an issue for me. I was actually driving home on Rt. 6 last night and it's pretty open there, yet the signal was in and out the whole way to Orleans.
In LA, I used to park my car under a tree near my house, in LA, and it worked fine when I started it up. Power lines were not a problem. There was only one dead spot on the Hollywood Fwy. and that is the only time it ever cut out for me.

Have your antenna looked at. If you are dropping signals, the antenna is a likely suspect. I've changed a couple.

You probably didnt have problems in LA because of repeaters. A lot of major metropolitan areas have ground repeaters which keep the incoming signal strong. I actually live right outside of Boston and the reception is much better in the city as opposed to the tree and powerline covered suburbs. It's one of the major drawbacks of the system.

If you are having issues in open areas, it might just be a bad antenna.