I heard about Marco's shop from another mechanic, Kevin, who specializes in E46 M3s.
I needed some AC work done (vacuum, recharge, check for leaks, etc...) on my 04' M3 before I would be taking a couple of road trips into the desert this summer.
I asked my guy Kevin who's good for this sort of thing and without hesitation he mentioned Marco at Marco Polo Independent, he said he always takes his E46s here after an engine swap to get AC work done.
Marco and his apprentice Shawn were both very professional, cordial, and most importantly, honest. They let me know that my car was fine on Freon, so they didn't charge me for that. They could have easily pocketed the money, but they chose to be honest and lose some themselves.
They also worked very quickly, I dropped off the car at 12pm, and by the time I had finished lunch my car was ready.
I'm happy to report that my M3's AC has been blowing ICE cold this whole summer.
I will definitely be coming back next time I need some work done.