Wolfgang WETS might leave a little bit of oily residue behind on interior surfaces. If as you say you have used it for such, you might notice that the product does dry after application and after a time sitting.
But I've noticed that it sometimes doesn't dry 100%. I would think if you notice any oiliness left behind when you wipe panels-etc with your hands, and wish to eliminate it, a light wipe with a dampened Microfiber Towel should mostly rectify such.
For interiors plastics, I think you would be best served as has previously been mentioned, to go with and use a dedicated interior protectant.
More recently, I've been using Blackfire's Interior Cleaner, and their Multi-Purpose Protectant, and these are two very nice products indeed. Check them out. I can say without reservation that any of the PBMG House Brands designed for such should all work admirably.
(PS: Mike P might be possibly out on one of the Road Shows, thus might have only limited access at the moment)