Keep in mind too, that when you rent a Mini-Van with Dollar you are no longer confirmed to have a Grand Caravan. You are now confirmed to have a regular wheelbase Caravan. When you go to the check in counter sometimes they will assign you a Grand Caravan many other times they will give you a Caravan and make you pay to upgrade to the Grand Caravan if you want it. Be very careful with this, the upgrade charges vary. This happened to me on a trip during the middle of last year and due to the size of the party, I had to pay about 4.00 per day over my 2 week rental to get the Grand Caravan. I emailed a few contacts at Dollar and they did confirm this is the new policy...
One last thing, and I asked Dollar about this as well... Not all their vans have the built in child seats, they will not guarantee that either.