That depends on various issues, first was it a certified used car? What was the year,model and make.
If it was a certfied vehcile, most manufactuers are required to run a vehicle history report, such as a carfax to determine title isues. How ever, this information is not always 100% accurate.
Was the manufactuers warranty still applicable or had it expired?
If it had a salvaged titled this of course voids in remaining warranty except for saftey recalls.
It's possible it could have been a salvage vehicle for flood damages, wrecks or other issues. If it was a total loss and rebuilt this could leave you at risk for serious saftey issues.
You should certainly speak with the owner or General manager of the dealership, if they are unwilling to assist, then call the manufactuers consumer hot line.
http://www.usedcarwise.com/page/page/2916466.htm
File with the bbb of course, they will have 30 days to respond to your complaint. Not that it will be favorable,but at least it's a step.
Jerry Christopher
http://www.usedcarwise.com
p.s. If you need further assistance, please visit my web site for my contact information, I don't post on here because of spammers. If you could provide more details then perhaps I may have a few suggestions.