What are some good tips on where to park a limousine when you are in the city?

I live in CT and I just took a part time job driving limo's and town cars. I don't take them in to the city too often, but when I can, I want to be able to park the limo and do a bit of site seeing myself. I found out the hard way that a lot of parking garages don't let limo's park there! Do any of you know of a parking area that will take limos? Where in the city do you think my best chances would be to get a spot to park?