The driver's seats in Jeep Grand Cherokees have been reported in multiple instances to become loose and eventually break off completely. This could mean danger in a car accident; it is possible that the driver could be flung out the window while still strapped in.
This is a common problem in Jeep Cherokees and Jeep Grand Cherokees, but it's most common in 1999-2004 Grand Cherokees. Jeepseatbracket.com went so far as to design its own bracket to repair the seat. If owners hear clicking sounds or notice wobbling seats, it is worth looking at, considering a loose chair could be both dangerous and uncomfortable.