M.S.
I used to work for GMAC and I saw so many people get ripped off by buying a brand new car and then driving it off the lot and getting in a wreck. IF you decide to buy new, or make payments, then I recommend GAP insurance! I covers the difference between the price of the car on the lot and what its worth once you drive it off. I am pretty sure they offer it for used cars as well. If you want to spend a lot and look for a pretty new car, then returned lease is the way to go.
If, on the other hand you are like me, (I have a 1996 Saab, and a 1995 Volvo wagon), which is sounds like you are, then go to car lots and drive what you are interested in buying. I bought my volvo from a reputable shop that lets you take them home and test drive them for the day and night. I highly recommend this, because 2 of the ones I drove had mild exhaust leaks that didnt' turn up in their testing, but when I drove the car to my sister's (she lives about 90 min away) I got headaches from it. I am highly sensitive so these cars wouldn't work for me, but the third one was a keeper!
I have gotten some great deals on Craigslist, and if you go to Kelly Blue book, Edmunds, and NADA, you will get 3 different prices, so you can see what you should get for a car, and what you should pay. Most private parties use KBB, but dealers use NADA. I would look at consumer reports and then look on forums for reviews. Also, look at how much you are going to have to repair, and if it is somehting you can do yourself, or if a shop has to do it.
When thinking of going with a van/SUV instead of using racks, look at gas. Will you need the storage all the time, once a week, once amonth, etc. This should influence what you buy.
Honda's and Toyota's are more expensive on CL, just like the dealer's because they hold their value. I looked at a van this last time, but the only one I could afford was the Previa (not good reviews on reliability) so I dont' recommend that one. I ended up with a wagon because it did what I needed and had a rack. But, my SAAB still gets better mileage.
When you go to the dealer and trade in a car, they like to wrap it all into one sale, but really it is 2 sales. One, you are selling them your old car, and two, they are selling you a new (to you) car. Rolling them into one is a great salesman trick to get you to spend more because it seems like less. I hope that helps some. Feel free to ask more questions ifyou need or want to. Its such a hard thing to do, good luck!
Oh, also, try putting in and out all the stuff you need to, like kids in carseats, carseats, sports equipment, etc. do they fit, does it work? that test drive thing is great if you can find it! My mom went so far as to actually rent the car she was looking at, and she was glad because she didnt' like it at all. That's another way to go.