What causes warped interior carpets?

[Stanley Rockafella]

The 99 S70 I'm looking to purchase has a huge lump in the back seat, on the floor. While it doesn't bother me, I've never encountered that on any car I've inspected, or owned.

I've ran a car report, and it's never been written off for flood damage or anything.

Any other ideas?

[vivalegreg]

somebody probably jacked the car up with a jack in that area underneath, pushing the floor up in the process. ive seen it on a few cars before..smh