Cheated by dealer, need legal help. Thanks!

We bought a New 2006 Honda Odyssey from Penske Honda at Ontario,California on May 6, 2006. Later we went service at same dealer, on service print out we found the 5yr/60K warranty will be expired on 11/02/2010 instead of 05/06/2011. And there were 3 service records between 11/02/05 and 12/16/05 which was before the date we bought the van. So we suspected the van was sold to someone else on 11/02/05. Then for unknown reason the van was returned to dealer, and dealer sold it to us as NEW one. We then run carfax and found our
suspecies is correct. The van was sold to someon on 11/02/05. It is a pre-owned
one!

Today we also went to local DMV to confirm the carfax result. The DMV told us
the van is still under 1st owner's name and title was issued to other owner.
We have the buying contract clearly list "New" with 52miles on it. And carfax print out shows 1 owner on 11/02/06. The dealer cheated us and we have clear evidence!

Now I need suggestion from your guys. What I should do in this case? My friend
suggest us go to dealership ask a replacement. I feel it is not enough. Any
other suggestion? Should we sue the dealer? What we can get for the law sue if we win?