Why are there so many refurbished AVIC-Z1s?.. I'm curious as to many bugs and defects with the first generation?.. and if I bought a refurbished one, is that safe?

I think you're seeing a lot of refurbished ones because the Z1 is discontinued and the Z2 is the new model and there are many who are upgrading (just a thought... might not be the case though).

But, to ease your worry about Refurbished Z1s, I got one and had it installed over a week ago, and it looks and runs like new. Haven't had any problems at all with it yet (knock on wood). I saved about $500-$600 buying it and I could not be happier. But if the extra money spent is worth your piece of mind, I'd say get one new, if you can find one.