Hey Kevin,
I bought my '07 v6 limited used with roughly 28k. I looked it over REAL good, checked carfax, test drove it, did the brake without holding the wheel for alignment issues, crawled underneath with a flashlight, checked all the rubber parts both in the engine and boots, all lights working, manual in the glove, brake pads for percentage of wear, etc... pretty much all the normal stuff. One thing I forgot to check was making sure I received two sets of keys with key fobs and a valet key. I also didn't realize that my truck came with an alarm, I think it's Toy's factory alarm but my key fob doesn't have anything extra for arm/disarm so I'm not sure if the used dealer was suppose to give me another key fob for the alarm. Anyhow, mine came with the tow hitch and Toy provides a receiver when you buy it brand new. I got the receiver as well.
About the extended warranty, I can honestly say I don't think I would ever buy one for a Toyota. I have 2 generations of Toy owners in my family. Starting with my Mom's 2 Celicas in the early 80's and then my Pops '89 sr5 22re truck. Then my wife's Sienna in '04 and now my '07. None of these cars ever gave us a problem. And many of them with through some rough years of wear and tear. To this day my Pop's '89 truck is sitting in my driveway and I can go out there right now - crank it, take it to home depot and hall all the stuff my wife wants done to the yard. So for me when purchasing my used '07 I opted out of the extended warranty. (Boy was the used dealer mad when I rejected all his tries on the ext warranty options) But hey, the warranty really is for each person's own peace of mind. My peace was without it - provided my history.
The '07 is a great year! Good luck!