Planning a honeymoon split between BA and Mendoza in late May/early June.

I'm pretty familiar with how visiting wineries works in California and the Mid Atlantic. Can someone give me an idea how this works in Argentina? I've read that calling ahead is nearly required (no problem). Mostly, I'm interested in more info on transportation:
- How do most people get around? Self-drive in a rental car (not preferred!), hired car with driver, or group tour?
- What is the approximate daily cost for car with driver and for group tour? I've found very limited info on this subject online.
- Do most people arrange transportation well before arrival, or is it reasonably safe to do so upon arriving in Mendoza?

Thanks for any info!