2. If you have one trip per year with rental car for 1500 miles, you still need same amount money to maitain your own car. Maybe you save half oil change money.
3. If you drive your own car, ten years later you will have a old car with 150000 miles. Otherwise you will have a old car with 135,000 miles. Both car will sell for same amount of money.
You keep a car and rent a car, you pay twice amount of money for 150000miles.