HI, decided that renting a car is best for the 21 days we will be travelling through Europe. Which Car rental company would you suggest I use? Will be picking up car in Paris on 6/28/18 and dropping of in MRS on 7/11/18 total of 14 days. We will be arriving from London into the Gare Du Nord at 9am. Would like to pick up the car there or somewhere close by. We will be traveling from Paris to Germany, Austria and back to France. Will not be travelling in any other countries. Also heard that there is a type of gas/oil that is less expensive than regular gasoline. Any suggestions are welcomed. Again, thanks for all of your help.