One of the most important reasons for scheduled service work by an accredited mechanic is that manufacturers require this in line with their car maintenance guidelines. Failure to comply may invalidate your warranty, resulting in you having to fork out money for repairs which otherwise would be covered by the manufacturer. It is, therefore, a good idea to familiarize yourself with not only when your car is due for its next service but also with the exact parts which will need to be replaced.
A car is likely one of the most expensive household purchases you will ever make, so it makes sense to protect such a financial outlay as best as possible. This not only includes looking after the inside or outside of your car but also the mechanical side of the vehicle. Having your car serviced regularly helps to maintain its value resulting in a higher sale price when selling the car (often more so than good bodywork).