character bumblebee, rammed into a policefficer's suv. >> the real-life officer was taken to the hospital with minor injuries and filming had to be halted. enough to get me to stop what i'm doing to take a look at that video footage. >> yeah. before many of us walk into a used car salesman's office, we're suspicious whether or not we are about to be had. >> oh, yeah. 37 million americans bought a used car this year, so how can you prepare yourself to make a deal, a good one? elisabeth leamy went undercover to find out. >> reporter: even people who love cars often hate car buying. we set out to change that by going undercover to show you how to haggle. >> let's do it. >> reporter: our expert, phillip reed of auto website edmunds.com. our mission, to buy a certified 2007 honda odyssey exl. our budget, no more than $25,000. >> we weren't just going in and playing games with people and