In my Subaru Outback install I use an Audiovox FM modulator set up with a relay pictured here. The relay is set up so it switches on the power to the modulator when the Empeg amp sense line powers up (whenever the Empeg is on, the modulator is on). This setup works well for me, I can't tell the difference between a very good quality FM radio station and the Empeg's sound. If I crank the sound on my HU and pause the Empeg, I do get a bit of alternator whine, but it is probably a ground problem somewhere and Subarus are notorious for it. You could try the FM Modulator anyway, it's cheap, and if you don't like the sound out of it, install it in your wife/friend/SO's car .