much, I'll assume you haven't become familiar with YugoBernie. He's here in NoVA and does a lot of work on many people's Zs. No, he's not a certified Nissan tech, but he's absorbed way more info than ten of them put together by just using the FSM as a pillow, not to mention all the experience he's gained from working on countless Zs. People have come from farther away than you to have him work on their Zs. If your Z can make the drive (somewhere around 2-2.5 hours), I'd recommend him over any dealership technician.