I carry around a 48incher and fits nicely under the rear seat.
Any thing bigger then that would probably have to go on a roof rack or basket.
If you're really planning on getting one ask yourself this question...
Where am I going to use it to jack the jeep up?
Stupid question but it will make sense in a minute.
Lots of people have the hi-lift jack but also have rock rails or a steal bumpers that can be used for lift points.
If you don't have any of those you will have to get a
Hi-Lift Jack Lift-Mate and carry around a jack stand to put under the tire your changing.
I just got mine because this past weekend me and a few others got our sliders installed.
Also if you want to save some money on the hi-lift I just purchased one from harbor freight of exit 19 on the southern state for 45 bucks. It doesn't have a fancy name but it will get the job done just like the name brand ones.
So when are you planning to wheel that thing?!?