If the carpet is intact, it can be cleaned up really well. I pulled my driver seats due to some stains that had gotten down the side due to spilled coffee. A couple hours with a scrub brush, some foaming carpet stain remover, some carpet cleaner solution, a sponge, and a wet/dry vac and it cleaned up so well it looks almost like new.
I started just cleaning the spots but it left such a clean spot that I decided to do the whole thing.
So unless the carpet is physically damaged, it's pretty sturdy and it cleans up real well.