There are a few dangers to keep in mind when lifting, especially when using a body lift. With a body lift, the center of gravity is the biggest factor since it is not split like it is with a spring lift. Also keep in mind that with a body lift, you may have to extend the steering shaft, clutch/gas/brake links, you will most likely have to extend the transfer case shift, and could have to relocate the radiator and other miscellaneous components. Poor quality body lifts used to sheer off in a bad accident which left many people injured (especially true with the old Jeeps) - which may be the source of your parents' uneasiness.