I'm assuming you don't want shiny like Johnny's car wash look right? Just natural and new?
If you want a literal all in one product that will clean and dress your leather seats/interior plastics, door cards etc (good for all surfaces), try Optimum Protectant Plus (it's labeled Leather Protectant but they are changing it, works great on all surfaces)
http://www.detailersdomain.com/Optim...lus_p_177.html
Leaves a natural, black look. Not shiny, but matte. I like it because it works great on the seats and you really can "dress" your whole interior with it, its a viscous liquid so I would either spray it on an applicator and work into the surface, or just spray on an MF towel and work it in (that's what I do).
For maintenance wipedowns on the interior (i.e. not dressing the interior) I usually use whatever Detail Spray I'm using for exterior work as well, or 1Z Cockpit.
http://www.detailersdomain.com/1Z-ei...mium_p_70.html