Buy Santa Fee used, pay attention to what?

Since we are looking for a new car, we would like to jump on the SUV shaft next. It should become a model from 2008, gasoline or diesel no matter. Gasoline would then be converted to LPG. It should not become a towing vehicle, but just sit high and travel comfortably. How are the qualities, should be paid attention? Up to now we drive a Passat 3c with 2.0 liter TDI and DSG automatic, so we are already a little spoiled. Especially the automatic is already very horny, but the dare is not free of defects From now on something should be in the house with little trouble but much joy. Good copies with leather and good equipment there is plenty around 1500€, only No go is this walnut plastic inside. How are the wartunsg intervals diesel/petrols? Thanks to you already