wliwl - The couple that we used would certainly take 4 adults easily with room to spare. As mentioned we were a group of five and our teenagers are all adult sized now.

There are many taxis avalable in Paris that will accomodate 4 people. But take only a Taxi Parisienne or you'll be overcharged.

Thanks to all for your responses! I now feel much more comfortable using the public bus for transportation per Robespierre's suggestions. We will use the mini van cab as back up if we chicken out (with Shandy's suggestions)because we don't speak french -- but this is all part of the advenure! We will be arriving during the day and all my kids are teenagers and can manage their own bags well. Also, I like to scenic bus idea and we will be purchasing passes for our stay. Thanks for the link too!

If you are going to get the Carte Orange get it in the Gare before getting on the bus.