I recently purchase an '06 RL. I want to replace the factory wheels and tires (PAX run flat system). Is possible to do this without major modifications? Any advice is appreciated. Thanks!

 

No big deal at all. Just pick out what wheels you want. You'll have to transfer the TPMS sensors from your current wheels to the new ones. The biggest issue I've run into is the spare tire. You'll have to either have the car towed if you get a flat, deal with having the trunk floor popped up from having a full size spare under there, or shell out some serious cash to buy an RL spare tire assembly.

This is the photograph gallery section BTW. You'd probably get better responses by posting in either the wheel/tire section or at least on the main 2nd gen RL page.

You'll also find that many of your questions can be answered by doing a simple search. I searched for "depaxing" and came up with all of this:
https://acurazine.com/forums/search....archid=6317769