How to fix the ground loop hum without sacrificing quality!

I had some envy of a friend who had an A2DP bluetooth set up in her Kia Optima, and so I absolutely had to DIY it in my Prius! Alas, as many of you have found out the hard way as well, the ground loop hum attacked! But I showed her who is boss without the quality-reducing ground loop isolator (and at a cheaper price, too!).

Short answer: ferrite chokes.

Longer answer: written up on my (ad-free) blog.

Thanks for reading and remember to always share your mods