Toyota Ground Loop fix installation

My dealer has informed me that they have received my ground loop isolator kit and have plenty of time to install it. I asked how long it would take to install the fix and the service writer said 1 hour. I said that's odd, I was told it should take about 2 hours and he said he'd check and get back to me. He told me that he checked with a mechanic who never had done one and he thought 2 hours seemed reasonable. He also asked the mechanic my other question. Does the dash need to be disassembled for the installation. He found out after asking that contrary to what he originally told me (which I already knew was wrong) that it required more than just pulling the radio out.

I was wondering if any of you have had this done to their 08 prius and whether there was any problems. I am most concerned about ending up with rattles in my dash after this is done - especially in light of there being seemingly no tech having ever done this at my dealership. I don't want to be the guinea pig.

Thanks in advance.

 

Did you notice any degradation in the high or low frequencies using the Toyota 'fix'. I remember reading about third party isolation devices that mess with the audio quality. Also, did it do what it was supposed to - remove the hum ?

Thanks !
Steve