Dealerships have to have special facilities to service them AND they have to ground them before servicing. You can just guess what happens to a person who touches a piece of ungrounded metal on a hybrid after an accident.
We haven't had to service our Prius and we've had it a long time. My husband has only changed the oil once or twice. You don't need to change the oil every 3 months.
The only thing has been replacing the tires.
Our last Dodge Grand Caravan was a piece of junk! After 7 years, the transmission went out on it. At that point, the driver's side window wouldn't role down, the cassette tape player and several speakers were broken, and lots of other little things were broken. We had other problems with the car previously, so we got rid of it.
Before that I had an Oldsmobile Cutlass, and it was even worse than the Dodge. It's transmission went out at 54,000 miles, and it always had things wrong with it.
The Prius is in the running with our Mazda RX-7 and the Toyota Celica. Both of those were great cars. However, I think the Prius has had less work than the Celica. The only reason why we got rid of the Mazda and the Celica was because they were 2 small for a family. We have to buy cars that fit 5 people.