You should get model year from the VIN code or the sticker inside the front passanger door or A pillar and use this for identification. New cars can be left rotting in storage for months or even years before being registered. I actually knew of a case where a guy traded in his 18 month old Wrangler for one in the showroom which, little did he know was actually built before the one he already had! The 10th digit of the VIN denotes model year. R is 1994, S is 1995 and so on. On the door sticker you should also have the build date. If you look there is an MDH code. This denotes the Month, Day and hour the Jeep was born, so an MDH code of 042214 would mean it was built on the 22nd of April at 2pm. This is important information when identfying vehicles from specific batches for recalls and the like. Also note that model years run September to July so you can have a 1999 model built in 1998 or 1999 for example.