BMW Plastic Emulsion cleaner is pretty good too, again, not too shiny
For stubborn marks I use Megs APC diluted (All purpose cleaner) Gets chocolate off the back seats no problem in my wifes Merc. Cheaper alternative is Tesco APC.
In terms of the seats, for leather I would use a Leather cleaner, followed by a conditioner, Gliptone is pretty good or try the BMW stuff. For cloth seats I'd use the APC diluted and wet the whole area to avoid 'spotting' the material. Always try a hidden area first though.