Not the Sidekick but I did have an HS-1500 on my roof in a restricted area at one point.
High Sierra recommends 8 each 10' radios and sells this kit http://www.hamcq.com/index.php?act=v...d&productId=72
Make your own, it's cheaper needless to say. I am not sure about the Sidekick but I also remember having to remove something from my antenna on the base, a coil I think. It's been several years now.
High Sierra will tell you via email if you don't have this in your manual.
How good was it? I would rate it as fair to good.
It worked better on the car and trucks I had it on.
Oh, and a hint, I used a very inexpensive extension cord, outdoor rated, for the control wiring to the roof. Cheap, you bet.
And just a warning, if I remember right they get $75 for the extension tubes.