Like other car parts that have been made to last longer, most car batteries are maintenance-free and can last more than three years. The first sign that may indicate the need for a new battery is if there is trouble starting the engine.
as your car gets older.
Monitor your brake pad thickness and don't let the pads wear down to metal. This will cause damage to your brake rotors (discs) at least and possibly your callipers as well. Rotors and callipers are much more expensive to replace.