Do you have any pictures of what the inside of the antenna looks like without the black cover on it, and what you actually cut off of the antenna?Yes I have Sirius, I pulled off the outer black cover took out the inside copper spring. From there I diked off the size I needed and trimmed the black cover also. Put it all back together and now I can park in the garage. The antenna is now 2.2 inches long.
I have not found the reception to have changed, but were I live there is not much in the way of radio AM of FM here anyway.