The Jurassic Park Jeeps #12, #18 and #29 all had Mopar Light Bars surrounding the windshield frame. Jeep #10 did not have a light bar (or roll cage) as it was all going to be ripped off the Jeep anyways. There are two variations of the light bar found on the Jeeps.

Jeep #12 had a full light bar with a special plate mounted to the top for mounting 4 Jabsco 135SL search lights. Jeeps #18 & #29 had the mounting tabs ground down as no lights would be installed. The basic light bar was also modified on all Jeeps as it was originally a three piece bar that bolted together. All the ligth bars on the Jeeps in Jurassic Park were shortened by 1″ and then welded together.

Here the light bar can be seen on Jeep #18.