IMCDb.org: 1987 Jeep Wrangler [YJ] in "The O.C., 2003-2007" via kwout
The jeep was a 1987 Jeep Wrangler, according to Internet Movie Cars Database.
The year seemed to agree with 1987 Jeep Wrangler models supplied by Google Images.
This car was destroyed by a light pole falling on it in the earthquake episode and Ryan had a different one in the series finale.
Watch The O.C. episodes, view pictures, and get episode information on [TV.com]9http://www.tv.com/shows/the-oc/episodes/).
Check this out! HuffPost TV shares 5 Stories You've Never Heard About 'The O.C.'.
And see a list of The 100 Greatest Movie and TV Cars of All Time from Edmunds.com.