Hello guys. I need your advice sana. Today is my last PMS (3rd year). That means my car is no longer under warranty

What do you think guys? They have offered me extended preventive maintenance service which includes free filter and oil, but this time I need to pay their service of 3300 pesos. Should I avail that or there's a better alternative to that??
Second, they highly suggest the service that they offering which is Decarbonized (or sounds like that) for 4400 pesos. Is it recommended to get that? (Actually I need to decide in an hour, sorry)
Lastly, ngayung wala na siya warranty, ano yung mga things na pwede ko na gawin sa car. I'm not enthusiast naman, but of course, little improvement would be nice :D.
Thanks in advance mga bros