Everyone knows the potential advantages of renting a vehicle. You get the freedom of the road and, in those parts of the world where the public transport system is not so hot, it's the only way to get where you want to go in a timely fashion. Yet we all have friends with horror stories about the poor service they received when collecting and returning their vehicles. Allowing for cultural differences and language problems, the first and best step to getting the best service is to write to the renter explaining your needs. Sadly, mental telepathy is still very limited and, unless you tell people what you need, they can only guess. When they guess wrong, you get upset and that's where the problems grow bigger. So a simple list of your needs - trying not to make them sound like a list of demands - will smooth the way. If you arrive and find things still not ready, show the email. This usually produces apologies and more urgent attention to those needs.
Let's start by thinking about your choice of vehicle. If you have children or a lot of stuff to carry around, remember some countries prefer smaller cars. Telling the renter what size of vehicle you need is essential. Put the other way round, if you want to make the biggest savings, you're going to want the smallest, most fuel-efficient vehicle on the lot. Now come to the driving itself. In the US, we're used to automatic transmissions. In other countries, stick shift is the norm. If you can't drive a stick shhft or you're worried about a stick shift using the "wrong" hand (yes, some of these pesky foreigners drive on the other side of the road), tell the renter you want an automatic transmission. Now start thinking about all that stuff. How big is it? For example, if you're off to a ski resort, do you want a rack on the roof to carry your skis and poles? Is one of your children young enough to need a special seat? Better still, if you don't know exactly where you're going, do you want a GPS system?
Now think about where you're proposing to drive. This is not something that needs to be cared in stone, but if you think you may go into different countries, remember to ensure you are carrying all the equipment required under local laws. For example, as of July 1, 2012, the French Government has decided you must carry a breathalyzer. If you fail to produce one when asked by the nice police officer with a gun strapped to his waist, there's an instant fine. It's about $15 a time and these police officers have radios so can ensure you get stopped every mile if you don't smile when asked to pay up. So ask your friendly a car rental company to stock up your vehicle with all the mandatory equipment for the countries in which you propose to drive. Ask for a list and know exactly where it is.