I would like to convince my wife to trade in our Sienna for a Prius. We are a family of 5 and most days there will be no issues. The one week out of the year we do drive to NC for a beach vacation. Not sure how we could pull it off in a Prius. Thanks
Rent a larger vehicle for that week, get a Prius v wagon or consider a '12 HyCam. Not sure if your space concerns are more about passenger room or cargo capacity though. Consider the cost of renting that larger vehicle for a week on an annual basis vs. keeping the Sienna or buying a vehicle that's a guzzler to a Prius or HyCam.
May I be cruel? 51 weeks of Prius v MPG * your distance + 1 week of van rental should be cheaper than 51 weeks of Sienna MPG * your distance + 1 week of Sienna ownership to NC and back. Minivan Rental - Enterprise Rent-A-Car I chose the Prius v as you will have 5 people and it is wider. It also has a big enough cargo area you may not need the van. My v is new, and so far I am down about 3 MPG from my 2009 Prius, but it is a much larger car for my use. (cargo)
We both have economical autos for city use. We also have a 10 year old SUV gas guzzler with less than 100k miles that we used for trips thats cheap enough to be purchased without a loan.