Basically, flying to the USA and not taking one's own car, does make sense, even if the trip is to be a little longer. Should it be a round-tour, one soon discovers that the prices, even if it's for the same category car, are by no means the same. Thus, e.g., the extra cost for a slightly longer flight to Washington D.C., is distinctly lower, than for a rental-car, let's say for 5 weeks.
Don't be afraid, do it like we did and take the smallest catergory. It is still almost as big as the Golf which is familiar to us here. Indeed, one has to be determined, because they will really try to convince you to take one from a larger catergory.
In our case, they had a good reason for doing this, because a, by American standards, small car like this, wasn't even in stock on the enormous parking lot. Thus we had to, fitting in with our calculations, by necessity, take a ChevroletImpala (six cylinders, 24V and 3,9 liters capacity), of course, at a discount price.
However, you are advised to be careful. Our inclination to reject all additional offers, referred originally to the complimentary insurance, which, in the event of damages, would have released us from any personal-risk excess. In the end, we changed our minds and decided to take the additional insurance, and, due to the fact that our car was broken into in New York, and the bill was clearly lower, the decision proved to be a wise one.
In this case, one has to take up the cudgels for the rental agency and the then favourable exchange rate of the Euro. Would you rent out your almost new mid-range car for five weeks with unlimited mileage (in our case, 16.000 km), and only charge €1000, including insurance?
One wonders how the car rental companies actually do that. One answer is that here the cars are sold with partly incredible discounts by the manufacturer. The second reason is to be found in the statistics. If everyone would ride as much as we had done in America, the car hire companies would soon be bankrupt.
So there are plenty of people who just have a rental car in the resort before the door, and then did not cover many kilometers with it. There are also areas in which one can not drive that far. Those who e.g. afford a rental car in Mallorca, despite the relative size of the island will probably not cover a distance of 16,000 km in five weeks.
That rental car on vacation are still very popular, the German Federal Railroad had to experience bitterly. Their car trains were so little frequented, that they had to be abolished. After all, for the environment it's probably a profit. 12/14