2011 is the first year for the 3.6 engine. depending when built, they have cylinder head problems,timing chain problems. If you look at a 2011 maybe all the bad ones have been repaired by now?This is not an engine for a back yard do it yourself kinda person can do.yes the 3.6 does get decent MPG's and has some getty up and go as well. I have a 2010 and it has the plastic key as well. I had a 1998 grand caravan and it got better fuel economy than this 2010 with a 3.8 and 6 speed transmission does.I have had this 2010 for about 6 months.2013 could be a push button ignition switch. key just has to be present in order to start. different system.