"Should/must", No. Highly recommended, YES! First off let me admit I'm biased. For every vehicle I've ever own I take it to the dealer while it is still under warrantee. They not only do a better job at inspecting what is needed, updating any software, and implementing any recalls, it also eliminates any and all issues regarding your warrantee. Unless you misused the car if there is a mechanical issue it's their responsibility no questions asked. In addition you will find that having a thick folder paper trail of all service performed by an authorized Porsche dealer will make your resale much easier and perhaps more lucrative. IMHO