Passenger side under the rear seat? I thought maybe it had an exhaust leak at some point in its 28 years. Thanks.

 

Probably 90%+ of XJs that are regularly driven where they salt the roads have some rust (they are all now 15+ years old now after all, and very few vehicles in salt country that old that are driven in winter don't have rust), the only question is usually how bad. I've seen plenty of "Flintstone specials" (floors completely gone) and transparent rocker panels, if you only have that one spot consider yourself lucky (and fix it before it gets any worse, with a hole water will get in and cause more rust). Yes, your suspicion of an exhaust leak (or even being close to the pipe without adequate heat shielding) is well founded, heat cycles will accelerate rust (both by causing coatings to fail and affecting the metal itself).

 

yes.. a few places.. and some I just found.. going to address them all very soon... make her mint again...

 

Looks like it rusted from the inside out, this is caused by leaking door seals, carpet gets wet, rust floor beneath it. My jeep did the same thing, absolutely no rust anywhere else but the floor board was all crap. Mine rusted holes behind the rear seat as well.

 

Xjs are known for rust,And living in a place that sees snow and road salt its even worse.

 

I just got done replacing 80% of my entire floor boards. Chewck my build thread out to see the progress, don't want to upload all the images here. It wasn't so bad, just time consuming and you need to know how to weld.