On our recent trip to Ireland I booked as much stuff as I could before we left and paid with US dollars. It's just more economical with the exchange rate.
So when I was able to book a mini van for a week for $440.35 through Hertz I jumped on it. What I was told to expect was a Ford Galaxy or similar. OK, that looks like it should work for 3 adults, 2 children (in carseats) and luggage.
When we arrived to pick up the car we found that mini van translates to “7 passenger vehicle” in Ireland. Which is not the same as a mini van. (I wish I could tell you what it was, but they don't show it on their website) It's more like a small station wagon (think Subaru Outback). Needless to say, there was no way we could fit my mom in the back seat with two carseats. It was narrow and had low clearance. With all the driving we had planned there was just no way we could use it for a week.
After walking through the lot with an agent and looking at all the cars in the class we had chosen Doug & I were forced to admit that they were all too small; we would have to upgrade. Luckily there was one Land Rover with a manual transmission. You pay much more for an automatic transmission in Europe.
We took it- and paid in euros (therefore almost tripling our car rental costs).
Now I want to let you know that it was about the best decision we could have made. The ride was comfortable and there was plenty of room. We didn't complain one bit about the extra cost.
But just so you don't make the same mistake as I did… I highly recommend calling the rental company a couple of days before you leave, just to confirm your reservation. At that time ask what kind of car you can expect- there are many European cars that we just don't have here in the US. Go online and research that car. If it just won't do for your family and plans call back and see what is available for an upgrade. And make your change online if possible. Or through your travel agent if you have used one. But be sure to pay in US dollars if at all possible. Until the exchange rate evens out it's your best bet.
And remember that European cars are often smaller. Gas is much more expensive over there- it averaged €1.27 litre while we were there. That's close to $6 per gallon. And larger vehicles use more gas.