May also want to dig around ye old "NYC - VCE $143" thread...
When I was there a couple years ago, I recall booking thru Altalia or Atalia tours web site? Can't remember exactly, but the car came from Avis VCE and was a Jetta Wagon. Perfect for the 4 of us w/luggage and our jaunt down to Florence. Worked out extremley cheap for EU. Anything else close was about 2-3 times the price. Sorry I can't remember more details...Lots of vino on that trip!