I used to sell cars, so I can give you a few hints...
1. Most car dealers use NADA guide to price their vehicles and to price your trade. They have a website
www.nada.com.
2. Edmunds.com has a ton of information on what other people are buying and selling their cars for in your area. They also have a ton of information, reviews, safety, etc.. Definately one to look at prior to your purchase.
3. Use the autotrader.com, vehix.com, and cars.com to your advantage. Find pricing that you like for similar vehicles and tell the dealer "What other people are offering."
4. If you find a car you like online, try to get the dealer to give you a price over the phone. Give him an excuse that you are too busy, or you need to watch your kids. But be educated...know as much about the vehicle as you can, therefore he won't think of you negatively.
5. Always try to buy a car at the end of the month, or during crappy weather. Most sales managers try to get as much as they can sold at the end of the month, so they are more likely to make a deal. Rainy crappy days, not too many people are looking at cars. You can use this to your advantage, since they are more likely to get a car sold.
6. Don't get sucked into the "What do you want your payment to be?" If you give them a number, then they may not give you the best deal since they can make the payment work.
Good luck...car buying should be fun and not an unpleasant experience.
4-Runners are cool, but small inside and a gas hog.
Highlanders are small as well, but have better gas mileage.
Any Toyota or Honda will have better resale than most other vehicles.
You are going to loose a ton of cargo space when switching to an SUV....as well as the wide open sliding doors.