I installed this cargo rack for better rear storage. The rack is large, sturdy and does include tie-downs for when my TJ's top is off. The rack and brackets are sold separately, and fits both TJs and two-door JKs. They also sell a version for YJs.
I really like the rack, although I had two problems while installing.
First, the supplied black painted lock nuts needed to be replaced. I assume due to that they were painted, the process ruined the nylon/ plastic inside the lock nuts and literally made them as hard as a rock and impossible to drive the screws through them. I ended up replacing the lock nuts with new ones.
Secondly, two of the four supplied knobs with screws in them that fit around the lower part of the roll bars were not long enough due to the padding on the roll bar (the screws on the knobs are about a quarter inch too short). To fix this, I replaced the knobs with longer screws, however having the knobs fit would be better to easier remove the rack when needed.
My hounds can also sit on it when the hardtop is on for a great view. Here they are testing it out.
Dog bed setup for the hounds for a long Jeep trip. I also added a net to keep them from flying forward incase of an emergency stop. They love the view.