Is the warranty an AcuraCare warranty? If so, it only transfers in a private transaction, so if you bought the car from a dealer, no transfer. You should have a copy of the warranty and the document will tell you the administrative procedure to transfer. I would suspect you need the seller's signature.
2017 MDX Advance, White Diamond Pearl/Espresso
2007 Lexus LS460
2013 Lexus ES300h
2000 Chevy Silverado 2500
Previous MDXs: 2001 Touring, 2005 Touring, 2011 Advance