Convertible top goes up, no problem, down you must keep hitting switch. Problem?

Dave, in your opinion which tires are the best for the Z.

Tires? Very hard to say for sure; it depends on many factors, like your budget and intended longevity, and even if you need "all season" or performance. I would recommend hooking up with a local trusted tire specialist who can show you all the differences and available options. As a matter of personal standard, Michelin makes the best tire in the business in quality and workmanship, and typically best all around -- can't go wrong. That said, Pirelli and Continental will have some great choices available. Last, Hankook offers good value and performance.