Indeed, there's not much carpet left to stain when you put in the rubber floor mats, and the best leather products are Lexol and the ones stated above.. Not to mention, an annual shampoo of the carpets works wonders.. Mine have been through 4 years of muddy Boy Scouts and look new after I drag the carpet cleaner out to the garage..
On a side note, you can buy that 3M UV and chip protector by the roll for around $30. Do your headlights- they stay looking new, and won't fog up over time.. Go price a new headlight and you'll see why I mention it
Good Luck,
Mike