In my somewhat limited experience---I've done a half-dozen of them over the years---roll bars/cages that start out as a kit are mostly some variation of one-size-fits-all. They intrude massively on interior space.
I had a cage put into my daily-driver/ECTA record-holder Lincoln LS when I got serious about racing it. There simply isn't any sort of 'kit' for that purpose available and I had it done from scratch.
It's tucked as tightly as possible against the perimeters. Back seat knee room is compromised. I have no use of the glove compartment and the halo bar gets in the way of the sun visors.
On the other hand the kids working the drive-through windows at some of the local burger joints seem to appreciate the looks of it.
![Grin ;D](http://fepower.net/simplemachinesforum/Smileys/default/grin.gif)
KS