Before you begin your quest to actually buy a used car online, it would be a good idea to know the current blue book values of the vehicle(s) you are looking for. Visit Kelley Blue Book or NADA.com. Print out the comparisons so that you may shop with some sense of the going rate with the features you are looking for.

You can search, review and buy used cars online at a number of sites. For example, Autobytel.com offers you the ability to shop their virtual "Certified Pre-Owned" Cyberstore or the automotive classifieds. Our test search for a used Lexus GS400 resulted in 3 vehicles within 32 miles of our office. 

Our visit to stoneage.com allowed us to select a used vehicle by choosing year, make and model, then presented us with what amounted to be the current blue book values- both wholesale and retail. Additionally, we were able to select the options, colors, type of financing, and apply for an extended warranty all on the same form. 

Good Luck!