As far as the carpets and mats are concerned, you will never go wrong with Folex and a good APC. Folex can be picked up locally at Home Depot or Lowes, I think even Target carries it. And its relatively inexpensive.
Normally I give the carpets and mats a good pre-agitation with a stiff bristle brush followed by a thorough vacuuming. Spot treat any stains with Folex full strength. Apply a carpet foam work it in and re vacuum. Or (depending on the severity) I use the LGCM to extract . Then concourse if you so prefer.
The headliner spots may need an APC sprayed on a MF and worked that way. Maybe a Woolite solution? I am sure someone with more experience can chime in on this one. However be sure NOT to saturate your headliner, as any liquid may decrease the integrity of the glue and it may start to sag.
Sounds like the leather may need rejuvenation, many on the site like the Leatherique product for serious correction. Just know that this product takes a few steps but it surely sounds like the benefits are well worth it. As far a maintainece goes, just search leather and you will find a miriad of products recommended by the members. Lexol, Pinnacle, Einszett, Connolly (if the leather is not coated).
Good luck, hope this helps.
