Plenty of cities have seats open to and from Europe in business class, right now. Other places are oversold. What jtf560 is absolutely true, but if the city you want to go to is wide open then the loads part is out of the picture and Europe isn't much hotter than most of the USA right now anyway (you in MEM?).

Wherever you go, if it ends up being a trip that takes place entirely within a city, such as spending four day in Paris itself, I would not even consider renting a car. Who wants to drive in traffic on vacation! The weather is nice and the public transportation is good when there's no strike going on.